My 2015 Roush rs3 supercharged , I’ve changed injectors, plugs , coils, VCT solinoids, no vacuum leaks, still has cylinder 4 and 8 misfires that doesn’t throw any codes, however from time to time I get PO316 multiple misfires in the first 1000 rpms of startup. There is an issue with coyotes of the valves on cylinders 4 and 8 of the valves wearing down to a knife edge. I’m gonna do a compression check on 4 and 8 this weekend , if they fail , I will have to yank the heads and get them reworked. BTW. I can watch the misfires on scanner for cylinders 4 and 8 and sometimes cylinder 2 power balance shows the same.
It is the intake manifold for anyone here that is still confused I changed the spark plugs coil packs weren’t the problem (P0300, P0304, P0307) I swapped the coil packs from 4&7 to other cylinders and still had misfire on 4&7 so it’s not the coil packs It’s the intake manifold and I’ll be swapping it in about a week so I’ll come back to this comment to verify.
Everyone I've talked to said it's the intake manifold even on every forum I've been on said if you changed the spark plugs, coils, wires then it's the manifold which is an easy fix but expensive
I just had my own version of this problem corrected (I had #8 misfire, multiple cylinder misfire codes) coming on and off. Not blinking, but rather on for a few days then off. Car would hesitate at acceleration especially uphill at low RPM, idle was ok. Ended up being air/fuel ratio flaps inside the air intake manifold not working properly. The solution was to replace the whole upper intake manifold. Hopefully this'll help someone.
Had this same problem and just changed out the in take manifold even though on the original intake the IMRC valves were apparently still functional. Did not fix my problem. Has anyone definitively solved this problem???
I’ve read forums... same issue happened to me to #8 cylinder misfire p300 and p308 codes on the forums said it’s the intake runner control module mines a 17’ with only 4K miles
same with mine, i have cold air intake, and long tube headers, i took the intake mani off and the runners open and close so idk what could be the issue maybe the tune
I have a 2017 GT I put long tube headers high-flow cats with a tune and began to have the same problems misfire 300 308 so then I replace the spark plugs coil packs and Upstream O2 sensors and I still have the same problem I took it to a shop and had a Dyno done on the car it's began to run better but still have the problem taking it in for a second appointment August 9th I will let you know what happened
I just had 2017 GT manual. misfire 8 and 7. stock. Ford told the dealer to do 2 types of back pressure tests on the cats. Dealer says issue with driver side cat and needs to be replaced.
Marcos Alber it didn't fix mine either. They then had to replace the intake manifold. Some value over the cylinder wasn't working. That did it. No problem for a month now.
@@5ohjack yes I do, I did a crank relearn ,I not seeing the misfiring problem anymore, but now I'm getting an annoying evaporative small leak detected code.
@@FJTabb I had a P0160 code when I did the swap on mines. Deleted the code and did a crank relearn and my car seems fine now . Did the crank relearn work for you too ?
Mine is doing the same thing, trying doing a data log with the Nguage and see if a tuner can read the file. He should be able to see if it’s on the fuel side or the air side.
My 2015 Mustang GT is at the Ford dealership now for this exact problem. I am disabled and can't drive my car often. Bought it Nov 6th 2014. The tech told me it was the "intake manifold valve that was broken". He said he had never seen anything like it before and is not sure how it would break. Reading the comments here apparently it's a big issue. He said bhai it wasn't stuck open or closed its just flopping around in there. Hopefully I'll get my car back tomorrow... if not it will be Tuesday... because of Labor Day. 2 weeks without my car.
Hey man know this is old but did you ever get this fixed? I’m reading online that it could be as small as coil packs and sparks plugs, or it could be an entire intake manifold :(
My car is in the shop right now for the same thing. They replaced the tone ring and the hub. Car is ideling rough and cylinders #1 & #7 are misfiring. Did you get resolution to this issue?
Hey Sylvester how did you ultimately fix this problem? Or Hey anyone on this thread who had this problem how did you fix it. I running E85 with an Nguage tune, I keep reading about E85 fouling the O2 sensors. also have corsa long tube headers with cat delete.
Having the same problems on my 17. Codes P0300, P0302, and P0308. Was going to take it to my dealer, but it seems like the Ford dealers have no idea what the problem is or how to fix from the comments...Also I never had this problem until I had the clutch replaced at 30k (it's my first manual car, so I tore though the clutch pretty fast lol)
Literally the same exact problem I had. My clutch went out at 112,000 miles. ( pretty good life actually) and when i got it back it keeps throwing p302 and p308. I'm going to try the crank relearn today! 2015 mustang gt performance pack
Ivan Dobronizski i have a 2017 gt pp i got the check engine light i run the codes im getting codes p0300 and p0308 i took it to dealer they check every thing and they told me it was a bad catalytic they change it i got the car yesterday and the same day i got the check engine again so the car was in the dealer for 2 weeks for no reason is the third time i take the car to service and they did a multipoint inspection and they say everything is good. I dont know if they are just being lazy or they can figure it out.
Thanks, i just change the oil and spark plugs and clear the check light! And after i get some speed and check light get flashing like crazy for like a minute or less and just went clear! i really don't know what is happening too my car! Right now i put spec stage 3 clutch and AFE power intake!
jevin ayson well as far as the sensors going off. Yes they got all that to go away. I asked the manager what the issue was and he just said he didn't know that they just got the warnings to go away. But with the loss of power. nope! They said the car wasn't throwing any codes saying cylinder misfire so they told Me to take the car back and drive it until it threw codes again.
Bro im goin thru the same shit with my mustang. I brought it into ford 4x already since may 2019 we are now in October n its still misfiring. Ford replace purge valve,catalytic converter, VTC, and still misfiring idk what to do at this point.
@@Manuelgomez-yx6vp i brought my whip to ford in Bridgeport Connecticut they suck. Ill never buy a ford product again. I ended up just givin the car back n copped a acura
@@papabear311 i think about just trading in the car, very upsetting, i thought it was my intake so I removed and put the stock one back on and its still having the same issues, keep in mind its a 2019 gt!
Andy Sanchez not yet brother. Bought spark plugs. Autozone didn't have the coil packs in stock on island so I'll swap SP first then work my way down the line.
My 2015 Roush rs3 supercharged , I’ve changed injectors, plugs , coils, VCT solinoids, no vacuum leaks, still has cylinder 4 and 8 misfires that doesn’t throw any codes, however from time to time I get PO316 multiple misfires in the first 1000 rpms of startup. There is an issue with coyotes of the valves on cylinders 4 and 8 of the valves wearing down to a knife edge. I’m gonna do a compression check on 4 and 8 this weekend , if they fail , I will have to yank the heads and get them reworked. BTW. I can watch the misfires on scanner for cylinders 4 and 8 and sometimes cylinder 2 power balance shows the same.
Intake manifold bro! I have a ‘15 GT, once you hit 80 mph the check engine light blinks. I changed the plugs and coils, then finally the manifold
^^this!!!
This should be pinned
This is make a sense
I had the same issue yes it was the Intake manifold runners malfunctioning.
A mechanic told me to have my catalytic converters checked. The high back pressure from car can cause misfires. It may be the same with your car.
If you get anymore details let us know!! Hope you figure this out
It is the intake manifold for anyone here that is still confused
I changed the spark plugs
coil packs weren’t the problem (P0300, P0304, P0307) I swapped the coil packs from 4&7 to other cylinders and still had misfire on 4&7 so it’s not the coil packs
It’s the intake manifold and I’ll be swapping it in about a week so I’ll come back to this comment to verify.
Did you fix the issue?
Update???
Did you get it fixed , lmk please I’ve been having the same problem
Everyone I've talked to said it's the intake manifold even on every forum I've been on said if you changed the spark plugs, coils, wires then it's the manifold which is an easy fix but expensive
yea my car in the shop for this rn. cylinders 8 miss fire. intake manifold on back order… stuck paying for a rental smh
I just had my own version of this problem corrected (I had #8 misfire, multiple cylinder misfire codes) coming on and off. Not blinking, but rather on for a few days then off. Car would hesitate at acceleration especially uphill at low RPM, idle was ok. Ended up being air/fuel ratio flaps inside the air intake manifold not working properly. The solution was to replace the whole upper intake manifold. Hopefully this'll help someone.
deemas82 if its that then the solution is a roush supercharger lol
What are you talking about there is no a/f ratio flap
707 horsepower Addiction Probably IMRC’s?
Bro my car is misfiring and its so random ! Ford can't find any codes ! Its sucks
Had this same problem and just changed out the in take manifold even though on the original intake the IMRC valves were apparently still functional. Did not fix my problem. Has anyone definitively solved this problem???
I’ve read forums... same issue happened to me to #8 cylinder misfire p300 and p308 codes on the forums said it’s the intake runner control module mines a 17’ with only 4K miles
same with mine, i have cold air intake, and long tube headers, i took the intake mani off and the runners open and close so idk what could be the issue maybe the tune
I have a 2017 GT I put long tube headers high-flow cats with a tune and began to have the same problems misfire 300 308 so then I replace the spark plugs coil packs and Upstream O2 sensors and I still have the same problem I took it to a shop and had a Dyno done on the car it's began to run better but still have the problem taking it in for a second appointment August 9th I will let you know what happened
what happened?
Rick Cynthia Miller what did they tell you?
I just had 2017 GT manual. misfire 8 and 7. stock. Ford told the dealer to do 2 types of back pressure tests on the cats. Dealer says issue with driver side cat and needs to be replaced.
NYDP 77 I hear that brother. My set up has catless mids.
NYDP 77 they replaced my cat and i still have the same problem
Marcos Alber it didn't fix mine either. They then had to replace the intake manifold. Some value over the cylinder wasn't working. That did it. No problem for a month now.
I'm having this problem now with a ported 18 manifold on my 16 gt. Mine has no loss of power but it throwing that same code on my Nguauge
Do you have the IRMC lockouts?
@@5ohjack yes I do, I did a crank relearn ,I not seeing the misfiring problem anymore, but now I'm getting an annoying evaporative small leak detected code.
@@FJTabb I had a P0160 code when I did the swap on mines. Deleted the code and did a crank relearn and my car seems fine now . Did the crank relearn work for you too ?
Do a crank relearn with your programmer.
Mine is doing the same thing, trying doing a data log with the Nguage and see if a tuner can read the file. He should be able to see if it’s on the fuel side or the air side.
My 2015 Mustang GT is at the Ford dealership now for this exact problem. I am disabled and can't drive my car often. Bought it Nov 6th 2014. The tech told me it was the "intake manifold valve that was broken". He said he had never seen anything like it before and is not sure how it would break. Reading the comments here apparently it's a big issue. He said bhai it wasn't stuck open or closed its just flopping around in there. Hopefully I'll get my car back tomorrow... if not it will be Tuesday... because of Labor Day. 2 weeks without my car.
Most say if you replace the intake manifold. Problem fixed
Hey man know this is old but did you ever get this fixed? I’m reading online that it could be as small as coil packs and sparks plugs, or it could be an entire intake manifold :(
My car is in the shop right now for the same thing. They replaced the tone ring and the hub. Car is ideling rough and cylinders #1 & #7 are misfiring. Did you get resolution to this issue?
I'm late but did the shop fix it? What was the issue as I have the same problem now
Hey Sylvester how did you ultimately fix this problem? Or Hey anyone on this thread who had this problem how did you fix it. I running E85 with an Nguage tune, I keep reading about E85 fouling the O2 sensors. also have corsa long tube headers with cat delete.
Your battery voltage is really low for being on.
Check your intake manifold.
Having the same problems on my 17. Codes P0300, P0302, and P0308. Was going to take it to my dealer, but it seems like the Ford dealers have no idea what the problem is or how to fix from the comments...Also I never had this problem until I had the clutch replaced at 30k (it's my first manual car, so I tore though the clutch pretty fast lol)
You need to do a crank relearn
Hurricane Logan yea get a crank relearn with a SCT X4 and it’ll be good
Literally the same exact problem I had. My clutch went out at 112,000 miles. ( pretty good life actually) and when i got it back it keeps throwing p302 and p308. I'm going to try the crank relearn today!
2015 mustang gt performance pack
I have the same problem with my mustang gt 2017 with manual gearbox!
It's giving me misfire from cilinder 7-2-4-8! What should i do?
Ivan Dobronizski i have a 2017 gt pp i got the check engine light i run the codes im getting codes p0300 and p0308 i took it to dealer they check every thing and they told me it was a bad catalytic they change it i got the car yesterday and the same day i got the check engine again so the car was in the dealer for 2 weeks for no reason is the third time i take the car to service and they did a multipoint inspection and they say everything is good. I dont know if they are just being lazy or they can figure it out.
Thanks, i just change the oil and spark plugs and clear the check light!
And after i get some speed and check light get flashing like crazy for like a minute or less and just went clear! i really don't know what is happening too my car!
Right now i put spec stage 3 clutch and AFE power intake!
My 2015 GT is doing the same thing!! #3 & #8 cylinders
joe jorgensen it's a pain in the ass!
How did you manage to fix it
What was it?
Why do ppl take there car to the dealership to have work done is beyond me they never fix shit. Take it to a performance shop they actually help youn
Warranty lol
So what was it?
Did they fix it yet? I am having the same issue 😔
jevin ayson well as far as the sensors going off. Yes they got all that to go away. I asked the manager what the issue was and he just said he didn't know that they just got the warnings to go away. But with the loss of power. nope! They said the car wasn't throwing any codes saying cylinder misfire so they told Me to take the car back and drive it until it threw codes again.
Did they mention that the intake mani was cracked ?
jevin ayson nope. I don't know if they're just lazy but they couldn't figure it out.
Sylvester Hernandez does your car feel like its cutting fuel on a cruise on 3&4 gear 2k + rpm?
jevin ayson YAAAS!!!!!
Bro im goin thru the same shit with my mustang. I brought it into ford 4x already since may 2019 we are now in October n its still misfiring. Ford replace purge valve,catalytic converter, VTC, and still misfiring idk what to do at this point.
Yo man my car is also misfiring , they can't find any codes its insane!
@@Manuelgomez-yx6vp i brought my whip to ford in Bridgeport Connecticut they suck. Ill never buy a ford product again. I ended up just givin the car back n copped a acura
@@papabear311 i think about just trading in the car, very upsetting, i thought it was my intake so I removed and put the stock one back on and its still having the same issues, keep in mind its a 2019 gt!
its the head gasket ! just change it ! check your exhaust if it has some liquid ! check it with your finger
I bet a Whipple would fix that problem...😊
did you get that problem fix cause I'm having the same issue...
Andy Sanchez not yet brother. Bought spark plugs. Autozone didn't have the coil packs in stock on island so I'll swap SP first then work my way down the line.
Sylvester Hernandez YEAH man I did the same thing but it went away for a while then it came back...
Did you guys ever figure it out im having same issue
Geez just tell us what fixed it
Help me mines in acting up
Having same issue here man