Just got home from long day at work. I got so many notifications. Was undecided on who to watch first, but Ivan!!! Yep. You're first to watch :) absolutely love your channel!
Dude thank you so much for this case study. I learned a lot. I’m going to try that on my Audi A6 2001 running rich at 25% with horrible stalling misfires. As a paramedic we have differential diagnoses based on vitals, signs, symptoms, ekg, tests. That is called internal medicine, diagnosing based on assessments, vitals, tests, signs and symptoms; to dig deep and finding the right diagnosis for a problem that is not outright obvious. You are doing the same but just in the car world. I applaud that you are acting like a true automotive technician.
Last winter my 02 Durango had a bad o2 the fuel trims went to 33 short and 33 long term so rich it stalled out flooding the plugs and did not set a o2 code or lean code . It set a p0129 baro code goes prove that you don't replace parts on code alone . Great vid :)
Finally, got some time to catch up on your videos. Well, done. From the beginning couple things came to mind such as clogged cat. timing, and O2. Do this next time. Go to oxygen data in the scan tool and look for current data pid and it would read 0ma compare to the other bank. This will definitely cut your diag time. Wait until you get 07 gm truck with same symptom and codes but it's a wild ride. Also, with buick enclaves. Good luck brother.
You are 100% correct about the test drive being critical. Sometimes what one person perceives as being the problem may be totally different from what the actual problem is. I've seen some techs that think a car has a transmission issue only to find a problem with the ignition system.
Ivan, Great job as always. I have a '04 5.3L that came from the factory with the wrong plug wires installed that developed similar random misfires. That engine comes with either Melco (Mitsubishi) square coil packs or the Delphi round design packs that use two different length wires. The Melco requires a 10.5 inch wire and the Delphi use a 9.2 inch wire. RockAuto lists both types of wires and packs if you want to see a picture. Anyway the shorter wires will reach the square packs but are stretched like a piano wire and begin to fail intermittently after time. Just something else to watch for. When in doubt, buy the longer ones. Looking forward to your next video.
Frank, I have seen the two different coils/wires setups on these trucks. Will make sure to keep an eye out for those stretched wires. Thanks for the tip :)
I want to go to Staten Island University! Nice detective work Ivan!!!! You're getting quite the reputation in State College !!!! I agree with the other gentleman in a previous comment. Why the heck will GM not flag a bad O2 sensor? Of course the ECM can detect exactly what's going on with this O2 sensor. Come on GM pull yourselves together and fix this problem !!!!! Nice work Ivan !
Good fix, what I kept going back to after you commented on vehicle having multiple converters, that vehicle warming up problem getting worse, thermal failure. What I really take away from this is the tools you must have to work on the modern vehicles, as opposed to the old ones that I still drive and am able to work on. Anyway good job!
Dang it, I misread that waveform. I honestly didn't know what to attribute that super long burn time too but now it makes sense since the fuel was so excessive that it wasn't being consumed. Great lessons here Ivan. Thanks so much for sharing!
Initially, at idle when the trims were fine but misfires were still being detected? I'd say because of the fouled plugs. What do you think? (this could be a nice whiteboard video Ivan!)
wow that thing was dumping so much gas i bet eric could taste it lol. you sure kieth wasn't sitting at one of those dunkin doughnuts? hats off to you ivan on the format on this 2 part series. i enjoyed reading the comments and seeing where everyone was going on this. some made sense and some.. well.......... .
Yeah. You got me with that one Ivan. The fuel trims didn't seem to out of whack when you looked at them on the car park. Nothing beats a good test drive and fuel trims are king above all else really.
Very cool . I had my share of ignition and o2 related cars this week , it can certainly be taxing ... but it's relaxing to sit back and watch you figure out yours ! Lol Great content as usual sir !
Aha! A loose spark plug, well that explains the low compression on#2 @ idle and ignition waveform. The answer was at 0:44 @ part 1: P0174. Did we check the freeze frames for that?
Another great diagnosis to learn from, never suspected the O2 sensors as the data looked good before the test drive. More good info to commit to the memory banks, trouble is the memory banks aren't what they used to be :). Thanks again Ivan.
Well in the past Champion had a sandblast apparatus, but left sand in the sparkplug will ruin the engine so use soda instead. Some mechanics are just burning the coal with a torch but i think it's not good for the isolator. th-cam.com/video/fGLNHkNu9gU/w-d-xo.html
Yes I am. I am now on a quest to learn more about diagnostics using scanners. You bring a lot to the table with your case studies, regardless how simple they are for you. Keep up the great work Ivan.
Cool! I have a PP4 sitting on the shelf here, waiting for some experimentation and critical evaluation. I already did a review on Dan Sullivan's LoadPro, that was a lot of fun :) On modern cars sometimes all you need for a diagnosis is a good scanner and critical thinking!
I agree. There are many ways to reach a diagnostic conclusion with computer controlled systems and you have shown that the most powerful tool for getting a clear graphical picture is a good scanner with scope. Its fun to watch how you walk us through the process and include the challenges you are facing along with the solutions. I watched your review on the LoadPro. Very understandable and you showed all angles, both the advantages and disadvantages. Every tool has its application. You will find the PP4 to have some cool features that help the technician save time in probing for voltage readings, continuity testing, resistance testing, and some other things. Where the Power Probe really shines is in its ability to activate certain electrical components with Power and Ground. Of course it can't be compared to applications where a scope and scanner are best suited. That is where watching you use those tools to find solutions is really interesting and fun. Keep going, I like to learn too.
I'm far from being the expert here,but I did comment in the first video about the lean code... Out of that list of codes you had initially,the lean code would've been the first I'd attack with misfires. What was the reason the PCM set a lean code if the fuel trims were fine?
Yes Nick, you were spot on that the lean code was key! Apparently the failure only occurred once the vehicle is driven and the oxygen sensor gets really hot. Freeze frame data should have shown us this :)
Old time technique, visual inspection, test drive, mechanical inspection. Damn computers made some issues easier, and some issues more difficult to spot. It was so nice they left #2 unplugged for you....
Great video Ivan. That explains the intermittent long burn time 3ms and higher and the low burn line which happens on a rich mixture . Scope waveform was spot on! Reading the plug would have shown rich also but the waveform read it perfectly. Great call on the test drive nailed the O2 sensor. Check out the TSB 05-06-04-063 LM7, L59, or L33 Engines With Cold Start Rough or Inconsistent Idle, Misfire, MIL "On" or Flashing Requiring O2 Sensor Replacement & PCM Reprogramming... Again great video series Ivan!!
You are the TSB master, Bob. Thank you for looking that up! Yes, the scope was not lying. Now can you see the difference on the waveform between a rich mixture, and an actual misfire on a fouled plug? When I took the initial capture, the mixture was GOOD, but we still got the bad waveform, indicating the plug was already fouled on the previous run :)
Pine Hollow Auto Diagnostics Yep I learned how to read secondary patterns on a Sun scope at BOCES in NY in 73-74 and they are a great diagnostic tool but some inductive pickups don't give the details. I used to use my Snap-on scope but the Pico has such a better waveform. That waveform also look similar to a spark plug that was just starting to carbon track especially the way it dissipated the energy at the end and the long burn line. Rich fouled spark plugs waveforms look the same after 40+ years. Just think we were the ECM & O2 sensors back then & rejetted carbs, air bleeds, ign timing, changed spark plug heat ranges, etc nut now it's done in micro seconds. Reading spark plugs has become a lost art & the base of the plug is where the real reading is taken. If I can have easy access to a plug I yank it out and it tells a story and saves time sometimes. TSBs also have saved me from chasing my butt over an issue that is corrected by a software upgrade. Eric actually posted it before me I just piggybacked on his post. Your diagnostic skills are impressive Ivan...Look forward to your next video.
Hayward's Automotive I do Love really you Guys, discussing and sharing your experience with us. I appreciate it by heart. Try to learn for sure.. in the First video; Waveform 2ndry Spark, Spark Burn Time apparently looked long. Spark Line high; lean mixture & Spark Burn Time long; rich mixture. At Test Drive O2 acted up and so it helped to conclude. I honestly liked much Ivan's ideology that Test Drive helps to see more better what's going on. Thanks Ivan
Good job Ivan, lambda sensor fixed low! I'm always interested in the bank specific misfires you guys get over in the States because I get so few V engines to work with over here in Ireland, just the 3/4/5/6 pot straight petrol and diesels!
Yes, it is very helpful when you have a "known good" bank to compare to! I've seen some 4 and 6 in-line engines (Toyota, Mitsubishi, BMW) where the fuel systems are separated into two "banks"...
This was exactly what was wrong with my gmc sierra 1500hd at 350 000km. Great video. That computer save the parts cannon. I put lot's of parts in to it before o2.
Pine Hollow Auto Diagnostics well if anything I can say im glad you checked cyl 2 and found a loose plug. Wish we had the first 2 minutes of this this video on part one. It was key information. None the less good job!!! Little staged and set up but good job hahahahaha I'm certain the issue was known before record was hit 😂😂😂😂 love you to Ivan even though you set me up 😋
WOT is in open loop in most engine management systems. Make sure the cat is not damaged on bank two. They can heat up and burn from the excess fuel but very good catch. Thumbs up 👍👍👍
Ivan, thank you for taking the time to make these videos. I was wondering if it would be possible to help DIY people like myself without expensive diagnosis machine. Could you suggest a cheap tester in the $100.00 range. Something that can read codes and suggest possible problems. Thank you for your help
Thanks! But please review the footage in Part 1. The fuel trims looked perfect even during the misfires. At that point the O2 sensor was still working just fine :)
I’ll have too. I could have sworn you only showed them when it was running good. It’s amazing what you can figure out when you know how to read fuel trims along with O2 sensors. Great job!
any harm in just leaving that upstream O2 sensor unplugged, long term that is? assuming it gets replaced at some point, but shaking at idle is no bueno.
Ahh, not what I was expecting! Post cat sensor told the tale! I missed that in the first vid. In the beginning of this video, I thought you were going to say, "So ... on this truck, .... I'd like to bounce it off a few trees and set it on fire". HAAHAHA! I don't think this one had you THAT stressed out though. That's just how my mind works late at night. :D
Ahh yeah, I have a bad habit of forgetting things minutes after. Good example of how you've got to test drive vehicles to get all the right info! I've got lazy in the past and not taken a vehicle for a ride, figuring it would take too long ... but that came back to bite me in the ass big time! The longer you watch the data, the better! Great vid man!
Haven't drove it yet but mine drove fine but at idle it would misfire I just unplugged 02 sensor it worked perfect as of right now hoping that's the problem really thankful for this video!!!
In theory could you have unplugged the coolant temp sensor to keep the ECM running in open loop which ignores the O2 sensors until warmed up?? Or am I thinking of something else that is ignored in Open loop??
No soldering or bonus footage at the end?? What gives? haha Nice find, really amazed me how the test drive gave the evidence needed to find the problem. No O2 codes....just shows how dumb some cars still are.
I have a 2007 Tahoe that misses on bank 1 after changing motor mount ran great before that changed plugs,wires,o2 sensors,coil harness did all that after I found broken ground wire that is repaired still not fixed any help welcomed
Haha yeah I mean I know the scanner & data were showing 'correct' data (C'mon it's Snap-on, not like it's an Autel complete with Chinglish translations) but yeah! I don't recall seeing the temp guage on cold in part 1?!
Could you take the oxygen sensor with the correct signal and splice the signal into the bad signal wire from the other bank, in affect disconnecting the bad sensor, and using one sensor to run both banks, would the strength of the signal be enough to fool the computer.
Great question, Charles! Might have to try that out at some point. Not sure the computer would like the two O2 sensor inputs being tied together...especially on this system with the bias voltage. But it just might work!
you could maybe build an o2 simulator that you could dial in using a trim pot. biggest problem would be all the different connector ends. then you could dial rich or lean to see how the computer reacts
My old '03 Saturn Ion had something similar - the O2 sensor would be fine shortly after you started it up, but after driving it a while so it got fully warmed up it would just pin itself lean and eventually started setting B1S1 low voltage codes. Could be GM got some bad O2 sensors around that time period that would crap out like this.
I have GMC Acadia 2010 75 k km , misfiring 2,4,6 cylinder with LTFT bank 1 is -8% and bank 2 is -13% change spark plug, ignition coil, ECM, fuel injectors, but still misfiring when cold start, can you advise me
I would definitely be warning the customer that it's very likely a few codes and possible a clogged or melted Cat may be coming in the not so distant future as a result of running rich for any period of time instead of just bringing in to be fixed right away.
hello i have a 2007 avalanche and i have many misfire i was told by chevy place and put sensor lifters coils spark plug wire crankshaft oil pump i have little power now after driving it for two day chevy recommend new engine should i go that route are can my engine be save please someone help me
Not sure just running super rich would kill it. If there's no oxygen left in the exhaust it can't really burn anything off. Misfires are what will really kill them because you get a full cylinder worth of both unburnt fuel and oxygen.
It's a catalytic reaction, it doesn't "burn" anything with free oxygen, that is the whole point. Why do you think it's called a CATALYTIC converter? Think about what happens for a moment before posting misleading junk, how much free O2 do you think your exhaust gasses have at stoichiometric or at an enriched condition? When do you have the most hydrocarbons, CO and NOx to break up?
Cat has for sure taken a beating, excessive heat kills them good. But there is quite a margin between a pristine cat to when the ECM sets MIL due to cat degradation. He might have just saved it...
Big Cheese, please do some research before calling other's posts "misleading junk". Robert H is absolutely right in this case. A cat would suffer if you feed it raw gas and oxygen = FIRE! In this case with a rich mixture there is very little oxygen (and no raw gas) in the exhaust stream. Homework assignment: write down the main chemical reactions that occur in a three-way catalytic converter. What are the input and output gases?
Ok, interesting. My belief is that running very rich absolutely risk prematurely destroy the catalytic converter. I'm actually quite sure that is the case. But I'll see if I can catch some dude or dudette researchable on the topic later this week... :) Meanwhile, my understanding is that a rich condition, without any misfires contributing with free oxygen in the exhaust gasses, can cause a catalytic converter to fail and do so reasonably fast. Equally true goes for a misfiring condition that creates blowtorch-like conditions when igniting in the cat, no one should doubt that. But a cat isn't a burner (and here is where I might've been clearer) thus operating outside its intended range can/will cause premature failure. Unlike a burner, an automotive cat has the reduction and oxidation process taking place on the molecular level of a surface layer called the washcoat. The washcoat is a highly porous coating made up by a metal oxide which covers the entire honeycomb structure making the exposed surface area ridiculously large. This coatings purpose is to suspended the working bits (which is minute traces of precious metals such platinum, palladium e.t.c) in something that exposes them maximally to the gasses streaming by, It also needs to provide a high temperature resilient base for them to sit. Not only will this delicate concoction of chemical and micro-structure brilliance be exposed to super hot, corrosive combustion products, the actual reactions taking place on it also releases massive amounts of heat as well. Even though metal oxides are resilient to both abrasion and temperature, it all ends up in an expensive and quite delicate device. This is the explanation to the verity of cat failure modes: * Clogging up with combustion particles (Most likely because of soot from a rich condition or excessive oil entering the combustion cycle) * Cracking in the honeycomb, restricting flow (because overheating or thermal stress) * By damage to the washcoat (overheating or faulty combustion) * Driven up on a big rock (i.e flat cat) * It's nicked (though, probably still working, just not on your car..) I'll take on your assignment tough, even though it's been a while since I did chemistry. Assuming you are referring to a standard Petrol engine 3-way catalytic converter. It'll look roughly something like this: Nitrogenoxides: NO or NO2 --> N2 + O2 (Note, these lets go of oxygen which later can be consumed in following processes! Redox?) Hydrocarbons: HxCy + O2 --> CO2 + H2O (highly exothermic) Carbonmonoxide: CO + O2 --> CO2 (oxidation) Here is an interesting question though, will a severe lean condition cause possible damage the cat (ignoring the fact that other components probably would fail before the cat)?
Awesome video! Love watching the master of diagnostics at work! Thanks for once again taking us along.
Just got home from long day at work. I got so many notifications. Was undecided on who to watch first, but Ivan!!! Yep. You're first to watch :) absolutely love your channel!
Josh, positive comments like yours really brighten my day! Glad you enjoy the vids, thanks for being here :)
I had it figured for going lean, but suspected an intake manifold leak on that right bank maybe... Good find, Ivan. Love watching you solve mysteries!
Dude thank you so much for this case study. I learned a lot. I’m going to try that on my Audi A6 2001 running rich at 25% with horrible stalling misfires. As a paramedic we have differential diagnoses based on vitals, signs, symptoms, ekg, tests. That is called internal medicine, diagnosing based on assessments, vitals, tests, signs and symptoms; to dig deep and finding the right diagnosis for a problem that is not outright obvious. You are doing the same but just in the car world. I applaud that you are acting like a true automotive technician.
Last winter my 02 Durango had a bad o2 the fuel trims went to 33 short and 33 long term so rich it stalled out flooding the plugs and did not set a o2 code or lean code . It set a p0129 baro code goes prove that you don't replace parts on code alone . Great vid :)
Very nice diagnosis sir . Surprised it wasn't stuck lean all the time . Usually the intermittent o2 is reserved for the Chryslers
Might have nailed it in the parking lot if I actually looked at the Freeze Frame for the P0174 haha
Pine Hollow Auto Diagnostics If you ask me,I think you did it on purpose to keep us guessing and make for a good video. Lol!
thanks for the video
Wouldn't get code for unplugging O2 sensor?
Nick Nicu 😂😂😂😂😂
New Level Auto Always love Keith's entry by any means. You're teaching us nicely and motivating each other :)
Paul Danner is also nice among You.
Finally, got some time to catch up on your videos. Well, done. From the beginning couple things came to mind such as clogged cat. timing, and O2. Do this next time. Go to oxygen data in the scan tool and look for current data pid and it would read 0ma compare to the other bank. This will definitely cut your diag time. Wait until you get 07 gm truck with same symptom and codes but it's a wild ride. Also, with buick enclaves. Good luck brother.
Excellent diagnosis and video as always, thanks for showing us
Awesome, love your problem solving videos especially those where a pin in he connector is damaged/defective. Thanks
Love these case studies with the full size GMs :) Thanks Ivan.
Gotta love when Ivan figures out a tough problem. Like a kid on Christmas day! Ivan buddy amazing job as always!
That feeling is priceless indeed!
You are 100% correct about the test drive being critical. Sometimes what one person perceives as being the problem may be totally different from what the actual problem is. I've seen some techs that think a car has a transmission issue only to find a problem with the ignition system.
Ivan, Great job as always. I have a '04 5.3L that came from the factory with the wrong plug wires installed that developed similar random misfires. That engine comes with either Melco (Mitsubishi) square coil packs or the Delphi round design packs that use two different length wires. The Melco requires a 10.5 inch wire and the Delphi use a 9.2 inch wire. RockAuto lists both types of wires and packs if you want to see a picture. Anyway the shorter wires will reach the square packs but are stretched like a piano wire and begin to fail intermittently after time. Just something else to watch for. When in doubt, buy the longer ones. Looking forward to your next video.
Frank, I have seen the two different coils/wires setups on these trucks. Will make sure to keep an eye out for those stretched wires. Thanks for the tip :)
This is great info, Thanks!
I want to go to Staten Island University! Nice detective work Ivan!!!! You're getting quite the reputation in State College !!!!
I agree with the other gentleman in a previous comment. Why the heck will GM not flag a bad O2 sensor? Of course the ECM can detect exactly what's going on with this O2 sensor. Come on GM pull yourselves together and fix this problem !!!!! Nice work Ivan !
Good fix, what I kept going back to after you commented on vehicle having multiple converters, that vehicle warming up problem getting worse, thermal failure. What I really take away from this is the tools you must have to work on the modern vehicles, as opposed to the old ones that I still drive and am able to work on. Anyway good job!
Another great analytic diagnosis . I love watching your mind set , and you proving your conclusions. Also no F bombs today, LOL
Dang it, I misread that waveform. I honestly didn't know what to attribute that super long burn time too but now it makes sense since the fuel was so excessive that it wasn't being consumed. Great lessons here Ivan. Thanks so much for sharing!
Actually in Part 1 the mixture was just fine (stoichiometric)! Now John, can you tell me why we saw the long burn time? ;)
Initially, at idle when the trims were fine but misfires were still being detected? I'd say because of the fouled plugs. What do you think? (this could be a nice whiteboard video Ivan!)
Like you said, the necessity of the test drive is crucial.
One of your best friend very, nice job.
wow that thing was dumping so much gas i bet eric could taste it lol. you sure kieth wasn't sitting at one of those dunkin doughnuts? hats off to you ivan on the format on this 2 part series. i enjoyed reading the comments and seeing where everyone was going on this. some made sense and some.. well.......... .
You can command open loop with scan tool as another way to make ecm ignore o2 sensors. As always great to watch you go through your diagnosis
I just saw that in the "functional tests"... never tried that feature before!
Yeah. You got me with that one Ivan. The fuel trims didn't seem to out of whack when you looked at them on the car park. Nothing beats a good test drive and fuel trims are king above all else really.
Great job. Im watching you Ivan from Poland.
Great job Ivan.
Very cool . I had my share of ignition and o2 related cars this week , it can certainly be taxing ... but it's relaxing to sit back and watch you figure out yours ! Lol Great content as usual sir !
Lots of wrong guests in part 1. Thanks for another quality vid Ivan.
Aha! A loose spark plug, well that explains the low compression on#2 @ idle and ignition waveform. The answer was at 0:44 @ part 1: P0174. Did we check the freeze frames for that?
In this case I think the Freeze Frame would have been very helpful indeed. But then video wouldn't be as fun ;)
Very true (both) :-)
A great video again! Thanks Ivan!
isn t it funny how hind sight is almost always 20/20? lol
Yes it is, I beat myself that I did not catch that from the part one.
Bravo comrade. Vodka for everyone.on the house. Excellent job Ivan. We are proud of you here in California.
I'll go for some hot tea instead haha
Pine Hollow Auto Diagnostics next time your in the San Francisco bay area, hot tea is on me...a little vodka or tequila is optional.
Nice, another SF bay viewer. I'll buy Ivan's dessert after he finishes his tea :)
FORCED-INDUCTN deal...if he went to Montana to do a clutch im sure he would come to California for hot tea and dessert.
From Hercules CA! :)
Thanks Ivan, I learned something. Just curious why the unpluged sensor didn't set a code and turn on the check engine light.
It did set a couple codes, but needed another drive cycle to turn on the light :)
Another great diagnosis to learn from, never suspected the O2 sensors as the data looked good before the test drive. More good info to commit to the memory banks, trouble is the memory banks aren't what they used to be :). Thanks again Ivan.
Memory Bank 1 or Memory Bank 2? ;)
Whichever one has a little room left, they are both pretty full of useless stuff :)
Ive run into that before right after doing lifters on a 5.3. I believe when I pulled head coolant got on sensor causing the issue. Good job Ivan
Coolant and oil fouled sensors can do weird stuff for sure...
Blessings Dr Ivan..cheers🍸.
Nice fix Ivan. I suggest to sodablast all the sparkplugs just as a service to the customer.
Sodablast?
Well in the past Champion had a sandblast apparatus, but left sand in the sparkplug will ruin the engine so use soda instead. Some mechanics are just burning the coal with a torch but i think it's not good for the isolator. th-cam.com/video/fGLNHkNu9gU/w-d-xo.html
Nice job Ivan. Valuable insight. You are awesome!
Thanks Jeff! Are you the PowerProbe guy?
Yes I am. I am now on a quest to learn more about diagnostics using scanners. You bring a lot to the table with your case studies, regardless how simple they are for you. Keep up the great work Ivan.
Cool! I have a PP4 sitting on the shelf here, waiting for some experimentation and critical evaluation. I already did a review on Dan Sullivan's LoadPro, that was a lot of fun :)
On modern cars sometimes all you need for a diagnosis is a good scanner and critical thinking!
I agree. There are many ways to reach a diagnostic conclusion with computer controlled systems and you have shown that the most powerful tool for getting a clear graphical picture is a good scanner with scope. Its fun to watch how you walk us through the process and include the challenges you are facing along with the solutions. I watched your review on the LoadPro. Very understandable and you showed all angles, both the advantages and disadvantages. Every tool has its application. You will find the PP4 to have some cool features that help the technician save time in probing for voltage readings, continuity testing, resistance testing, and some other things. Where the Power Probe really shines is in its ability to activate certain electrical components with Power and Ground. Of course it can't be compared to applications where a scope and scanner are best suited. That is where watching you use those tools to find solutions is really interesting and fun. Keep going, I like to learn too.
Excellent work thanks! Have same issue now.
I'm far from being the expert here,but I did comment in the first video about the lean code...
Out of that list of codes you had initially,the lean code would've been the first I'd attack with misfires. What was the reason the PCM set a lean code if the fuel trims were fine?
Yes Nick, you were spot on that the lean code was key! Apparently the failure only occurred once the vehicle is driven and the oxygen sensor gets really hot. Freeze frame data should have shown us this :)
Life saver! Had the same truck 04 avalanche same exact issue! Same fix!
Yup common problem, easy fix :)
Old time technique, visual inspection, test drive, mechanical inspection.
Damn computers made some issues easier, and some issues more difficult to spot.
It was so nice they left #2 unplugged for you....
haha yeah good thing I peeked under the hood before the test drive!
nice find had me confused too didn't know what it was gonna be
Great video Ivan. That explains the intermittent long burn time 3ms and higher and the low burn line which happens on a rich mixture . Scope waveform was spot on! Reading the plug would have shown rich also but the waveform read it perfectly. Great call on the test drive nailed the O2 sensor. Check out the TSB 05-06-04-063 LM7, L59, or L33 Engines With Cold Start Rough or Inconsistent Idle, Misfire, MIL "On" or Flashing Requiring O2 Sensor Replacement & PCM Reprogramming... Again great video series Ivan!!
You are the TSB master, Bob. Thank you for looking that up! Yes, the scope was not lying. Now can you see the difference on the waveform between a rich mixture, and an actual misfire on a fouled plug?
When I took the initial capture, the mixture was GOOD, but we still got the bad waveform, indicating the plug was already fouled on the previous run :)
Pine Hollow Auto Diagnostics Yep I learned how to read secondary patterns on a Sun scope at BOCES in NY in 73-74 and they are a great diagnostic tool but some inductive pickups don't give the details. I used to use my Snap-on scope but the Pico has such a better waveform. That waveform also look similar to a spark plug that was just starting to carbon track especially the way it dissipated the energy at the end and the long burn line. Rich fouled spark plugs waveforms look the same after 40+ years. Just think we were the ECM & O2 sensors back then & rejetted carbs, air bleeds, ign timing, changed spark plug heat ranges, etc nut now it's done in micro seconds. Reading spark plugs has become a lost art & the base of the plug is where the real reading is taken. If I can have easy access to a plug I yank it out and it tells a story and saves time sometimes. TSBs also have saved me from chasing my butt over an issue that is corrected by a software upgrade. Eric actually posted it before me I just piggybacked on his post. Your diagnostic skills are impressive Ivan...Look forward to your next video.
Hayward's Automotive I do Love really you Guys, discussing and sharing your experience with us. I appreciate it by heart. Try to learn for sure.. in the First video; Waveform 2ndry Spark, Spark Burn Time apparently looked long. Spark Line high; lean mixture & Spark Burn Time long; rich mixture. At Test Drive O2 acted up and so it helped to conclude. I honestly liked much Ivan's ideology that Test Drive helps to see more better what's going on.
Thanks Ivan
Good job Ivan, lambda sensor fixed low! I'm always interested in the bank specific misfires you guys get over in the States because I get so few V engines to work with over here in Ireland, just the 3/4/5/6 pot straight petrol and diesels!
Yes, it is very helpful when you have a "known good" bank to compare to! I've seen some 4 and 6 in-line engines (Toyota, Mitsubishi, BMW) where the fuel systems are separated into two "banks"...
Nice diagnostic Iván ☺
thanks Ivan keep em coming
Nice one, Ivan!
This was exactly what was wrong with my gmc sierra 1500hd at 350 000km. Great video. That computer save the parts cannon. I put lot's of parts in to it before o2.
So could a plugged cat. converter cause the same symptoms? I too have misfires on one bank only.
Nice job Ivan, keep up the good work 👍🍻
Will do, Will :)
Pine Hollow Auto Diagnostics well if anything I can say im glad you checked cyl 2 and found a loose plug. Wish we had the first 2 minutes of this this video on part one. It was key information. None the less good job!!! Little staged and set up but good job hahahahaha I'm certain the issue was known before record was hit 😂😂😂😂 love you to Ivan even though you set me up 😋
I wasn't on Staten Island, so this one was 100% LIVE!
Pine Hollow Auto Diagnostics you did great 👍 I'm just playing with you
great 2 part video thank you
Thumbs up. I will watch it later i know you always delivered a good stuff. Lol
i wish you lived in chicago great diag as always
Chicago is the Mecca for mobile diagnostics! I think all the good trainers are from that area...
Amazing. Thanks Ivan.
WOT is in open loop in most engine management systems. Make sure the cat is not damaged on bank two. They can heat up and burn from the excess fuel but very good catch. Thumbs up 👍👍👍
About time nice diagnosis great job
haha thanks Leon! I was going to wait until tomorrow morning, but Keith finally posted a comment on Part 1 xD
Pine Hollow Auto Diagnostics I took notes and next I will do the same hahaha I will simply say need to see more 😂😉
Ivan, thank you for taking the time to make these videos. I was wondering if it would be possible to help DIY people like myself without expensive diagnosis machine. Could you suggest a cheap tester in the $100.00 range. Something that can read codes and suggest possible problems. Thank you for your help
Actron.
see, we could have known that in video 1 had you shown the fuel trims during the misfiring like I asked. ;-) Good videos brutha
Thanks! But please review the footage in Part 1. The fuel trims looked perfect even during the misfires. At that point the O2 sensor was still working just fine :)
I’ll have too. I could have sworn you only showed them when it was running good.
It’s amazing what you can figure out when you know how to read fuel trims along with O2 sensors.
Great job!
Brilliant as always Ivan! :)
Eh, just got lucky on this one by not digging a deep rabbit hole with those initial misfires ;D
All those new Dunkin Donuts are because they heard Keith was coming for a visit.
Exselecte diagnostic amigo nice video
any harm in just leaving that upstream O2 sensor unplugged, long term that is?
assuming it gets replaced at some point, but shaking at idle is no bueno.
Poor fuel mileage
DD is going strong thanks to some staten islanders.... great job comrade!
Thanks, Emanuel! There must be 100 DD locations on that island thanks to Keith xD
Pine Hollow Auto Diagnostics I might be joining DD anonymous
Ahh, not what I was expecting! Post cat sensor told the tale! I missed that in the first vid.
In the beginning of this video, I thought you were going to say, "So ... on this truck, .... I'd like to bounce it off a few trees and set it on fire". HAAHAHA! I don't think this one had you THAT stressed out though. That's just how my mind works late at night. :D
You didn't miss anything in the first vid! All the data was spot-on!
Ahh yeah, I have a bad habit of forgetting things minutes after.
Good example of how you've got to test drive vehicles to get all the right info! I've got lazy in the past and not taken a vehicle for a ride, figuring it would take too long ... but that came back to bite me in the ass big time! The longer you watch the data, the better! Great vid man!
Why did you have to take the truck on the road and how did that affect the 02 sensor ?
Got it nice and hot. Only then did it show the failure!
Thank u for sharing.
Was it unnecessary to check the wiring to the O2 sensor, because the engine ran better with it unplugged?
Haven't drove it yet but mine drove fine but at idle it would misfire I just unplugged 02 sensor it worked perfect as of right now hoping that's the problem really thankful for this video!!!
good job 👍
Ah okay, it makes sense now. It is a great video to confirm scopes are a needed commodity for a lot of diagnostics.
Well actually scope wasn't really needed in this case... Just scanner with decent graphing capability, and the mush between the ears lol
That's right. I lost my mind. :)
I tend to brake torque them hard for load tests also, just not for too long or too many times. if it allows it that is :)
part 3 = P0430 diagnosis lol . Great job
Ya they are Denso's Or buy the AC delco o2 sensor for More $$ and its a reboxed denso.
In theory could you have unplugged the coolant temp sensor to keep the ECM running in open loop which ignores the O2 sensors until warmed up?? Or am I thinking of something else that is ignored in Open loop??
No soldering or bonus footage at the end?? What gives? haha Nice find, really amazed me how the test drive gave the evidence needed to find the problem. No O2 codes....just shows how dumb some cars still are.
13:01 - XL7 , Krown or Not to Krown. Perhaps the Rogue instead of the XL7. ;)
I have a 2007 Tahoe that misses on bank 1 after changing motor mount ran great before that changed plugs,wires,o2 sensors,coil harness did all that after I found broken ground wire that is repaired still not fixed any help welcomed
Ivan I'm sure you showed fuel trims in part 1 & they were fine?!
Yup, that is accurate. Blows my mind too haha
Welloilbeefhooked!!! Just goes to show, never trust a scanner 100%!!!
Scanner was fine...so was the data. The sensor just needed to get hot enough to show the failure! That's the kicker lol
Haha yeah I mean I know the scanner & data were showing 'correct' data (C'mon it's Snap-on, not like it's an Autel complete with Chinglish translations) but yeah! I don't recall seeing the temp guage on cold in part 1?!
Why is the check engine light off with b2s1 unplugged?
Great question! It would take two drive cycles with the sensor unplugged to actually illuminate the check engine light.
Thanks! I would have thought that it would have set a code that would turn on the light pretty much instantly. I guess GM does things differently.
Could you take the oxygen sensor with the correct signal and splice the signal into the bad signal wire from the other bank, in affect disconnecting the bad sensor, and using one sensor to run both banks, would the strength of the signal be enough to fool the computer.
Great question, Charles! Might have to try that out at some point. Not sure the computer would like the two O2 sensor inputs being tied together...especially on this system with the bias voltage. But it just might work!
you could maybe build an o2 simulator that you could dial in using a trim pot. biggest problem would be all the different connector ends. then you could dial rich or lean to see how the computer reacts
My old '03 Saturn Ion had something similar - the O2 sensor would be fine shortly after you started it up, but after driving it a while so it got fully warmed up it would just pin itself lean and eventually started setting B1S1 low voltage codes. Could be GM got some bad O2 sensors around that time period that would crap out like this.
Ha at least yours set a code for a sensor, not just a generic (and false) "system too lean" :)
Good information thanks for it
Impressive!
Oooooh, a "Sample title" video!
Sweet!
:3
I have GMC Acadia 2010 75 k km , misfiring 2,4,6 cylinder with LTFT bank 1 is -8% and bank 2 is -13% change spark plug, ignition coil, ECM, fuel injectors, but still misfiring when cold start, can you advise me
Cam timing
Does it smell like raw gasoline or like sulfur (rotten eggs)?
It's a toxic smell...not raw gas since combustion is occurring, but a lot of hydrocarbons are not oxidized. Not quite rotten eggs either.
I would definitely be warning the customer that it's very likely a few codes and possible a clogged or melted Cat may be coming in the not so distant future as a result of running rich for any period of time instead of just bringing in to be fixed right away.
Side Note: Did you know there is a hidden 500GB partition on the D10 that snap on doesnt use for anything. I have Mitchell and save my waveforms to it
I have a 2005 Sierra with the 5.3L engine which coincidently has similar symptoms. Timely video for me. Thanks.
Nothin to it but do do it! Good luck on the repair!
Dunkin' Donuts = too far south for Tim Horton's !
Rather odd that the O2 sensor did not quit until it was fully hot.
I have the same problem but it runs better better when i unplug one of the bank 2 inyectors i plug it back i get back the misfire
there are 3 ignorant people out there as of now! Great video and diagnosis!
hello i have a 2007 avalanche and i have many misfire i was told by chevy place and put sensor lifters coils spark plug wire crankshaft oil pump i have little power now after driving it for two day chevy recommend new engine should i go that route are can my engine be save please someone help me
and i forgot to add trak trac control stabil light on
Wow sounds like a major parts cannon MISFIRE lol!
Facinating
So a bad O2 doesnt set a code?
Not always, as was the case here. That's why a scanner is only a tool, not a magic 8-ball.
I knew it couldn't be a weird bizarre thing.... It is not Staten Island. LOL
nice patience....
Yuo. Good tech.
I bet the plugs are fine... They're just flooded. Fix the O2 issue and the plugs will likely clean up fine.
With that bank running rich for so long, wouldn't that cat be destroyed by this point?
Not sure just running super rich would kill it. If there's no oxygen left in the exhaust it can't really burn anything off. Misfires are what will really kill them because you get a full cylinder worth of both unburnt fuel and oxygen.
It's a catalytic reaction, it doesn't "burn" anything with free oxygen, that is the whole point. Why do you think it's called a CATALYTIC converter?
Think about what happens for a moment before posting misleading junk, how much free O2 do you think your exhaust gasses have at stoichiometric or at an enriched condition? When do you have the most hydrocarbons, CO and NOx to break up?
Cat has for sure taken a beating, excessive heat kills them good. But there is quite a margin between a pristine cat to when the ECM sets MIL due to cat degradation. He might have just saved it...
Big Cheese, please do some research before calling other's posts "misleading junk". Robert H is absolutely right in this case. A cat would suffer if you feed it raw gas and oxygen = FIRE! In this case with a rich mixture there is very little oxygen (and no raw gas) in the exhaust stream.
Homework assignment: write down the main chemical reactions that occur in a three-way catalytic converter. What are the input and output gases?
Ok, interesting. My belief is that running very rich absolutely risk prematurely destroy the catalytic converter. I'm actually quite sure that is the case. But I'll see if I can catch some dude or dudette researchable on the topic later this week... :)
Meanwhile, my understanding is that a rich condition, without any misfires contributing with free oxygen in the exhaust gasses, can cause a catalytic converter to fail and do so reasonably fast. Equally true goes for a misfiring condition that creates blowtorch-like conditions when igniting in the cat, no one should doubt that. But a cat isn't a burner (and here is where I might've been clearer) thus operating outside its intended range can/will cause premature failure. Unlike a burner, an automotive cat has the reduction and oxidation process taking place on the molecular level of a surface layer called the washcoat. The washcoat is a highly porous coating made up by a metal oxide which covers the entire honeycomb structure making the exposed surface area ridiculously large. This coatings purpose is to suspended the working bits (which is minute traces of precious metals such platinum, palladium e.t.c) in something that exposes them maximally to the gasses streaming by, It also needs to provide a high temperature resilient base for them to sit. Not only will this delicate concoction of chemical and micro-structure brilliance be exposed to super hot, corrosive combustion products, the actual reactions taking place on it also releases massive amounts of heat as well. Even though metal oxides are resilient to both abrasion and temperature, it all ends up in an expensive and quite delicate device.
This is the explanation to the verity of cat failure modes:
* Clogging up with combustion particles (Most likely because of soot from a rich condition or excessive oil entering the combustion cycle)
* Cracking in the honeycomb, restricting flow (because overheating or thermal stress)
* By damage to the washcoat (overheating or faulty combustion)
* Driven up on a big rock (i.e flat cat)
* It's nicked (though, probably still working, just not on your car..)
I'll take on your assignment tough, even though it's been a while since I did chemistry.
Assuming you are referring to a standard Petrol engine 3-way catalytic converter. It'll look roughly something like this:
Nitrogenoxides:
NO or NO2 --> N2 + O2 (Note, these lets go of oxygen which later can be consumed in following processes! Redox?)
Hydrocarbons:
HxCy + O2 --> CO2 + H2O (highly exothermic)
Carbonmonoxide:
CO + O2 --> CO2 (oxidation)
Here is an interesting question though, will a severe lean condition cause possible damage the cat (ignoring the fact that other components probably would fail before the cat)?
Cool, looks like it ran great after you unplugged the Oxygen sensor and ecu went to default strategy...under 100,000 ks not many ks for a v8..
Awesome
Heard Krispy cream might buy D and D