I had to drive home on a missfire and after replacing the spark plug and coil was hit with "catalyst system efficiency below threshold bank 1." I didn't know what to fix and started running down a bunch of clean catalyst rabbit holes. Finally found this video. I've ordered a new O2 sensor thanks to you!!
Manufacturers program computers to cut off injectors to misfiring cylinders; as a result, you will experience a 25% drop in power. If the engine is a four-cylinder, your MPG will decrease by 10%. If that's alright with you, you can drive the car for as long as you want, assuming your country doesn't require emission tests. If it does, the only reason you need to fix it is to pass the inspection.
Thanks for this detail explanation. Had me wondering to know why check eng light kept coming back after replacing both 02s... since not replacing the head gasket seals, yet It been causing oil on the wires. Even though itvmay be 1 or 2 cylinder misfire only... 😮 need to get the gasket and seals replaced finnaly. Thanks bro
If the injector has missing signal, the computer cut off that injector. Then can I drive the car safely for some hundreds of miles until I get it repaired?
It has 6 cylinders, with 200HP. With 5 cylinder i still got 170. I just fear a little it can damage the catalytic converter. I've added some injector cleaner into the fuel to help out the remaining 5 injector. @@sheerwillsurvival2064
My moms car is a four cylinder and it had a P0304 and the check engine light was flashing. I actually seen a video talking about flashing check engine light referring to misfire and potential fuel getting into cat and damaging it. Idk if its true what another commenter said about manufacturers programming injection to cease in the event of misfire but me and my brother came to the conclusion to unhook that injector on that cylinder to keep fuel from reaching the cat and monitored how it was running on 3 cylinders. Didn't seem any worse so it was probably already only running on 3 cylinders. Hopefully the cylinder will be ok as long as its being oiled it should be regardless of combustion in that cylinder?
My 04 Sebring has a P0300 code (misfire on cylinders) and I took it to my mechanic and he said that the problem it is not the air , electrical, and fuel system but it could be the timing belt or worn lifters . What do you think it is ?
I have codes PO301, PO302, PO303, PO304. Car overheats from time to time I fill it back up with coolant. It is a 2001 honda civic. Do you think parts would be thst expensive for such a old car?
I ordered 8 fuel injectors and they delivered 1 😮. Amazon fixed the issue rt away though. I had a misfire on cylinder 4. Took the fuel injector out cleaned it up and codes went away. I don’t trust it which is why I’m replacing all 8. Fresh start. My question though. Is it true that can cause engine overheat? Needle goes up then bk down so idk what else might be going on.
I've done everything. I could to my trailblazer. We switched out the spark plugs. We switched out the coils we switched out. I am a gas thing. I don't know, but it's still only running on 5 and I can't figure out the problem. Maybe you can, is it the Cadillac converter right now? The engine light came on and my car shakes. It stays started, but I'm only running on 5. Can you tell me how to fix this? Or should I just take it into my mechanic? I have another mechanic and he's one that did the switching instead.All should be OK, it should be OK, but it's still running rough.Do you have any ideas?Thank you I don't have enough money to go to mechanic. That's why I chose this other guy who knows about cars and he got it running several times beautifully, but this time he can't seem to get what to do. He's done everything that the book tells him to do and still it doesn't. Change anything it still runs on 5 cylinders.
Not sure if you got this fixed since it’s been 2 months but changing the O2 sensors is worth a shot after you’ve replaced coils, spark plugs and valve cover gasket. I have the same issue, misfiring cylinder 2. Changed spark plugs, ignition coil and spark plug tube seals..no luck. I then plugged my computer in and got a threshold code for bank 1 and 2, or in other words O2 sensor. Replaced and fixed the rough idle and misfire.
@@Sohidden well I found out what was wrong the oil seal on the left hand side was bad so we changed it and everything's working right now, it was just an oil seal and it was leaking into my fifth spark plug put everything's going to be okay now thank you for getting back to me
I have a misfire the codes are 300, 303 and 305…mechanic did an compression test and said cylinder 3 should have PSI of 90 and above but mine is at 25 and told me I need a new engine…is this the case or can this be fixed without replacing? I have a 2011 Acura Mdx
What Catalytic converter? I had all three of mine removed years ago. I've been chasing a misfire code for about 2 weeks now It started as a P0303, I switched cylinder 3 and 6 coils around and the code was the same. Later it changed to a P0300, I replaced all 6 spark plugs and got one new ignition coil for cylinder 3. The misfire was still there and the code was back to P0303. I've been driving around like this for awhile now just waiting for this car to blow up lol. I'm still trying to figure out the problem, but at the same time I i dont care.😂
@@InnocentMondayMonday Funny thing is I found the problem. It turns out it was the injector wire on the connector, it was broken. I checked all six and what do know you all of them are dry and cracked. 😂
I have replaced, 4 coil packs, 4 plugs, 4 injectors, and I am still getting p0304 code. You can feel the slight missfire while idle but no loss of power while normally driving. Cam/Crank POS sensors were changed, no vaccume leaks, MAF cleaned. Wiggled the coil/ injector wires to see if possible issue and nothing.Did compression test and all cylinders are at 115-125psi dry and about just shy of 150 wet. Any ideas?
I had a misfire this morning… But I had put premium gas in my regular tank earlier this week and then my gas was low this morning. My car was shaking a little bit and the engine light was flashing. I drove very slowly and then it turned off.could this be related to me putting premium gas in my car?
sounds like an engine misfire. Best thing to do is to get an OBD scan tool and check for engine error codes. Or, some parts stores will scan it for free. Using premium gas in a car that only requires regular gas will never cause the issues that describe. At worst it might cause a very slight reduction in gas mileage
So I had a 4th cylinder misfire... I didn't do anything for about a month using my car. I initially changed all the spark plugs, but the problem still resided.. Then I changed one of the ignition coils. Problem went away. But the problem I'm seeing now is that the car is running rich. My mileage reader is saying its knocking down 2 mpgs at a time sometimes, or more frequently. If I put in new oxgen sensors, would the new one become contaminated??
I have a cylinder 5 misfire that I am unable to resolve. It’s a GMC canyon. I replaced the coils, spark plugs, and fuel injectors.I am going to replace the fuel filter next but I am sort of fearing the worse case. I also replaced the valve cover and gasket prior to all these replacements. You think I need a new engine? I have 327,008 miles on it right now.
@@InnocentMondayMonday no unfortunately. The next thing that I would need to do is replace the cylinder head and gasket. I believe the valve springs and piston valves need replacing. The cylinder 5 misfire causes the inside of truck to smell like fuel which is really bad. Can’t run AC bc of it. Overall, truck runs like a champ.
Got a question i just started my car (93 nissan 240sx) yesterday and it was having that missfire sluggish choppy idle even when driving it , would it be from my timing chain going out since its been rattling or my spark plugs that i havent replaced ?
if your timing chain is rattling, you better fix it. sooner or later it'll jump a tooth or 2 and smack your valves into the piston, and yes that'll cause a miss fire!
People with misfire you can’t fix check pcm mine just burned back somehow but still ran good would hesitate on light throttle heavy gas it was fine idk, plus my exhaust still leaks condensation driving for whole year
Hey. I have an 05 Cadillac cts. I changed the ignition coils, plugs, ecm, injectors and still misfiring. It shows multiple misfires when reading the codes. Car also shakes bad and has a ticking noise. Bad gas mileage. All plugs are sparking when I checked. Car seems to shake more intensely when unplugging 5 of the coils individually . However the 6th one there is no response or increasing shaking when I unplug coil;cylinder 5 I think. What are the list of possible problems and how to diagnose? Please help. P3831 P2098 P0140 P0036 P0008 P0301 P0306 P0305 P0300 P3537
Hello. I believe your timing is off thus causing a misfire. The misfire also ruined your oxygen sensor as well. #6 ignition coil is most likely bad (power balance test).
@@Top5AutoRepairs hi, thank you. my timing? Does that mean timing belt is the problem? I don’t have advanced computer reader, I’m a diy mechanic; just a basic code reader. Based off all info I’ve given, what can you recommend I try replacing , and in what order? Please bear in mind there is a slight clicking noise; someone mentioned it may be rocker arm and lifter. All ignition coils were causing spark when I pulled them out and held them slightly away from plugs .
thats how my old vauxhall/opel car died. neglected by cow boy mechanics, not changing worn spark plugs. also neglect from me, ignored the strong smell of fuel coming from exhaust. thwn was too late. changed spark plugs, coil and fuel injectors. didnt make any difference and dumped car. had for 13 years
Your holding something that most causes misfire, yet you talk too much about oxygen sensor that can be clean up and not talking about the thing that your holding ..
Not a problem with my old '46 Ford Jailbar which had multiple dead cylinders. No computer, no fuel injectors, no catalytic converter. 18 years no problem.
![สาวเมืองเพชร - ธีเดช ทองอภิชาติ [Official MV]](http://i.ytimg.com/vi/kEt7F9PvO3I/mqdefault.jpg)
I had to drive home on a missfire and after replacing the spark plug and coil was hit with "catalyst system efficiency below threshold bank 1." I didn't know what to fix and started running down a bunch of clean catalyst rabbit holes. Finally found this video. I've ordered a new O2 sensor thanks to you!!
How did you get on?
Exactly my problem. Legacy 2004 h6 spec b
@@mitz2772 still needed to replace the cat
Did the repair fix your issue?
Thank you for explaining. I just replaced o2 sensor but now i know what caused it to fail. Thank you Sir
Manufacturers program computers to cut off injectors to misfiring cylinders; as a result, you will experience a 25% drop in power. If the engine is a four-cylinder, your MPG will decrease by 10%. If that's alright with you, you can drive the car for as long as you want, assuming your country doesn't require emission tests. If it does, the only reason you need to fix it is to pass the inspection.
not all vehicles do that! I had 2 coils fail and i could smell raw gas!
Over time it can flood the engine and it could seize, just replace spark plugs first then wait for codes after that
Thank you brother I got a code of misfire on cylinder 3 i recently changed my spark plugs it cannot be the spark plugs time for new coil
It was the spark plugs actually that needed replacement lol i bought a coil for nothing
not for nothing bro now you know that you have a new coil if you need it better to be prepared than not be
@@yosoymichaelmyershow much was it to change the spark plugs
This is excellent information. This just happened to me 2013 Toyota Highlander 400 bucks because of mouse messed with it.
Thanks for this detail explanation. Had me wondering to know why check eng light kept coming back after replacing both 02s... since not replacing the head gasket seals, yet
It been causing oil on the wires. Even though itvmay be 1 or 2 cylinder misfire only... 😮 need to get the gasket and seals replaced finnaly. Thanks bro
Straight to the point
Great video. Also some manufacturers set computers to cut off injectors to the cylinder that is misfiring 👊🏻👍🏻
If the injector has missing signal, the computer cut off that injector. Then can I drive the car safely for some hundreds of miles until I get it repaired?
@@Knobber yes but it will be running rough
It has 6 cylinders, with 200HP. With 5 cylinder i still got 170. I just fear a little it can damage the catalytic converter. I've added some injector cleaner into the fuel to help out the remaining 5 injector. @@sheerwillsurvival2064
You’re the best. Thank you for all these tips.
My moms car is a four cylinder and it had a P0304 and the check engine light was flashing. I actually seen a video talking about flashing check engine light referring to misfire and potential fuel getting into cat and damaging it. Idk if its true what another commenter said about manufacturers programming injection to cease in the event of misfire but me and my brother came to the conclusion to unhook that injector on that cylinder to keep fuel from reaching the cat and monitored how it was running on 3 cylinders. Didn't seem any worse so it was probably already only running on 3 cylinders. Hopefully the cylinder will be ok as long as its being oiled it should be regardless of combustion in that cylinder?
Low compression, 5 of my cylinders read 140 and 1 of them reads 135. Is that too much of a difference that would cause a misfire?
My 04 Sebring has a P0300 code (misfire on cylinders) and I took it to my mechanic and he said that the problem it is not the air , electrical, and fuel system but it could be the timing belt or worn lifters . What do you think it is ?
I have codes PO301, PO302, PO303, PO304. Car overheats from time to time I fill it back up with coolant. It is a 2001 honda civic. Do you think parts would be thst expensive for such a old car?
I ordered 8 fuel injectors and they delivered 1 😮. Amazon fixed the issue rt away though. I had a misfire on cylinder 4. Took the fuel injector out cleaned it up and codes went away. I don’t trust it which is why I’m replacing all 8. Fresh start. My question though. Is it true that can cause engine overheat? Needle goes up then bk down so idk what else might be going on.
Wow! Thanks
I've done everything. I could to my trailblazer. We switched out the spark plugs. We switched out the coils we switched out. I am a gas thing. I don't know, but it's still only running on 5 and I can't figure out the problem. Maybe you can, is it the Cadillac converter right now? The engine light came on and my car shakes. It stays started, but I'm only running on 5. Can you tell me how to fix this? Or should I just take it into my mechanic? I have another mechanic and he's one that did the switching instead.All should be OK, it should be OK, but it's still running rough.Do you have any ideas?Thank you I don't have enough money to go to mechanic. That's why I chose this other guy who knows about cars and he got it running several times beautifully, but this time he can't seem to get what to do. He's done everything that the book tells him to do and still it doesn't. Change anything it still runs on 5 cylinders.
Not sure if you got this fixed since it’s been 2 months but changing the O2 sensors is worth a shot after you’ve replaced coils, spark plugs and valve cover gasket. I have the same issue, misfiring cylinder 2. Changed spark plugs, ignition coil and spark plug tube seals..no luck. I then plugged my computer in and got a threshold code for bank 1 and 2, or in other words O2 sensor. Replaced and fixed the rough idle and misfire.
@@Sohidden well I found out what was wrong the oil seal on the left hand side was bad so we changed it and everything's working right now, it was just an oil seal and it was leaking into my fifth spark plug put everything's going to be okay now thank you for getting back to me
Thanks!
Make a lot of sense.
Glad it was helpful!
on a honda accord 2017 which one is number 4
I have a misfire the codes are 300, 303 and 305…mechanic did an compression test and said cylinder 3 should have PSI of 90 and above but mine is at 25 and told me I need a new engine…is this the case or can this be fixed without replacing? I have a 2011 Acura Mdx
Informative
What Catalytic converter?
I had all three of mine removed years ago.
I've been chasing a misfire code for about 2 weeks now
It started as a P0303, I switched cylinder 3 and 6 coils around and the code was the same. Later it changed to a P0300, I replaced all 6 spark plugs and got one new ignition coil for cylinder 3. The misfire was still there and the code was back to P0303. I've been driving around like this for awhile now just waiting for this car to blow up lol.
I'm still trying to figure out the problem, but at the same time I i dont care.😂
Were you able to resolve the issue? course I am facing similar problem currently
@@InnocentMondayMonday
Funny thing is I found the problem. It turns out it was the injector wire on the connector, it was broken. I checked all six and what do know you all of them are dry and cracked. 😂
I have replaced, 4 coil packs, 4 plugs, 4 injectors, and I am still getting p0304 code. You can feel the slight missfire while idle but no loss of power while normally driving. Cam/Crank POS sensors were changed, no vaccume leaks, MAF cleaned. Wiggled the coil/ injector wires to see if possible issue and nothing.Did compression test and all cylinders are at 115-125psi dry and about just shy of 150 wet. Any ideas?
Same prob
@@392-oj-da-apeboys our transmission is gone 😔,gone continue driving till it goes out ig .Same problem
I’m wondering the same thing I have a misfire on cylinder 1, idle or low rpm’s are rough but smooth when up to speed or coasting.
@@FFARGONE yeeep same issue
I gotta Nissan doe ,wb yall
Hey man, love your explanations, vids. , T.Y. Q.Q. is it o.k. to mix manufactures when replacing cam,crank and coils ?
Yes it's fine
Do you think my car has gotten serious damage driving about 50km on a misfire
I had a misfire this morning… But I had put premium gas in my regular tank earlier this week and then my gas was low this morning. My car was shaking a little bit and the engine light was flashing. I drove very slowly and then it turned off.could this be related to me putting premium gas in my car?
sounds like an engine misfire. Best thing to do is to get an OBD scan tool and check for engine error codes. Or, some parts stores will scan it for free.
Using premium gas in a car that only requires regular gas will never cause the issues that describe. At worst it might cause a very slight reduction in gas mileage
How about them Piston rings? Melted valves? And burnt head gaskets?
I have a ford granada 1984 2.0 and it only runson 3 cylinders. How can I fix the car? I really don't watn to sell it.
So I had a 4th cylinder misfire... I didn't do anything for about a month using my car.
I initially changed all the spark plugs, but the problem still resided..
Then I changed one of the ignition coils. Problem went away.
But the problem I'm seeing now is that the car is running rich. My mileage reader is saying its knocking down 2 mpgs at a time sometimes, or more frequently.
If I put in new oxgen sensors, would the new one become contaminated??
How’d you fix your problem ?? I got the same problem right now
Did you fix it?
mine must be from spark cause i hooked it up to a skanner it said the emmision the igniton coil and spark plugs and bank 1 fuel rail is rich
I have a cylinder 5 misfire that I am unable to resolve. It’s a GMC canyon. I replaced the coils, spark plugs, and fuel injectors.I am going to replace the fuel filter next but I am sort of fearing the worse case. I also replaced the valve cover and gasket prior to all these replacements. You think I need a new engine? I have 327,008 miles on it right now.
Were you able to resolve the issue? course I am facing similar problem currently
@@InnocentMondayMonday no unfortunately. The next thing that I would need to do is replace the cylinder head and gasket. I believe the valve springs and piston valves need replacing. The cylinder 5 misfire causes the inside of truck to smell like fuel which is really bad. Can’t run AC bc of it. Overall, truck runs like a champ.
Got a question i just started my car (93 nissan 240sx) yesterday and it was having that missfire sluggish choppy idle even when driving it , would it be from my timing chain going out since its been rattling or my spark plugs that i havent replaced ?
if your timing chain is rattling, you better fix it. sooner or later it'll jump a tooth or 2 and smack your valves into the piston, and yes that'll cause a miss fire!
How can you fix an emission engine code P219D?
Is it possible that the ECU can cause an engine knocking ?
Yes or no ?
Unlikely. You're most likly to experience stalling, no start, multiple engine codes etc... caused by a failing ecm
People with misfire you can’t fix check pcm mine just burned back somehow but still ran good would hesitate on light throttle heavy gas it was fine idk, plus my exhaust still leaks condensation driving for whole year
Hey. I have an 05 Cadillac cts. I changed the ignition coils, plugs, ecm, injectors and still misfiring. It shows multiple misfires when reading the codes. Car also shakes bad and has a ticking noise. Bad gas mileage. All plugs are sparking when I checked. Car seems to shake more intensely when unplugging 5 of the coils individually . However the 6th one there is no response or increasing shaking when I unplug coil;cylinder 5 I think. What are the list of possible problems and how to diagnose? Please help.
P3831
P2098
P0140
P0036
P0008
P0301
P0306
P0305
P0300
P3537
Hello. I believe your timing is off thus causing a misfire. The misfire also ruined your oxygen sensor as well. #6 ignition coil is most likely bad (power balance test).
@@Top5AutoRepairs hi, thank you. my timing? Does that mean timing belt is the problem? I don’t have advanced computer reader, I’m a diy mechanic; just a basic code reader. Based off all info I’ve given, what can you recommend I try replacing , and in what order? Please bear in mind there is a slight clicking noise; someone mentioned it may be rocker arm and lifter. All ignition coils were causing spark when I pulled them out and held them slightly away from plugs .
what happens if i don’t replace o2 sensors
I have P0300 Code (Random misfire) 2013 challenger 6.4l how do I fix it!
Do you honestly expect an answer? Why not pay for a tech service or hire someone competent to diagnose and fix the issue. Geez!
Fuel would also cause a fuel lock similar to a furor lock
thats how my old vauxhall/opel car died. neglected by cow boy mechanics, not changing worn spark plugs. also neglect from me, ignored the strong smell of fuel coming from exhaust. thwn was too late. changed spark plugs, coil and fuel injectors. didnt make any difference and dumped car. had for 13 years
I been driving with a p0300 for almost 4 years 😅
I have a p0302 now drivig around with me for two weeks...i was paranoid until ibsaw your comment😂
@@antonymaduro4592- 😂 no question
Lol
My Madza 323f still misfire after changing spark plugs, coil
What happens if the ignition coil is loose
Do I have to replace the ignition coil is loose
If the engine knows there's a misfire why won't it it turn off the fuel Inkector
My coil pack is more exoensive than my O2 sensors. 😂
Your holding something that most causes misfire, yet you talk too much about oxygen sensor that can be clean up and not talking about the thing that your holding ..
His topic focuses on ***consequences *** if NOT fix misfire, NOT the causes of misfire 😅😅😅😅😅😅😅
Not a problem with my old '46 Ford Jailbar which had multiple dead cylinders. No computer, no fuel injectors, no catalytic converter. 18 years no problem.
the Crack head take my caterpillar conversion thing 😢
Your comment just made the right side of my brain hve a misfire😂
That was suler c,ear
My car is toast I need to sell it.
Same, idk if anyone will buy a broken car tho so idk what to do anymore 😅😭
Are not that👀👀👀 cheap 😂