B5 S4 P0302 Misfire
02-09-2014, 03:59 PM
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B5 S4 P0302 Misfire
I am having some issues with a misfire CEL on my 01 S4. Its the only code and I am at a complete lose to what is causing it. P0302 Cylinder 2 misfire.
I have done my fair share of research on misfire issues but mine seems so subtle that I think I'm over looking something.
A little history on what has happened.
The car originally had a valve cover leak and oil built up in the spark plug hole. I replaced the valve cover seal and cleaned the area well. I also installed all new NGK spark plugs. This was the first and obvious thing too fix. I cleared the code. However the car still felt like it had a little bit of a misfire at idle. It would smooth out once you hit the gas and there was little to no notice at higher RPMs. The code stayed clear for about a month.
A month later the code came back. My next attempt was to see if I had a bad coil. Since it was on cylinder 2 I swapped the coils around to see if the misfire would move to a different cylinder. again code cleared and stayed so for close to a month before coming back. Still P0302.
I figure that since it was on the same cylinder that it was possible that I had a bad ICM. There is two ICMs and they are the same. I figured that I would swap them and let the CEL come back. I was hoping that after swapping the ICMs around I would get a misfire code on a different cylinder proving that the ICM was bad. Well the CEL came back but its still P0302.
My question is what other conditions would cause a misfire on a specific cylinder? I am trying to wrap my head around this from a electronics point of view. what conditions triger this code in the ECU? I am open to suggestions at this point since most of the threads all talk about what I have tried so far.
I have done my fair share of research on misfire issues but mine seems so subtle that I think I'm over looking something.
A little history on what has happened.
The car originally had a valve cover leak and oil built up in the spark plug hole. I replaced the valve cover seal and cleaned the area well. I also installed all new NGK spark plugs. This was the first and obvious thing too fix. I cleared the code. However the car still felt like it had a little bit of a misfire at idle. It would smooth out once you hit the gas and there was little to no notice at higher RPMs. The code stayed clear for about a month.
A month later the code came back. My next attempt was to see if I had a bad coil. Since it was on cylinder 2 I swapped the coils around to see if the misfire would move to a different cylinder. again code cleared and stayed so for close to a month before coming back. Still P0302.
I figure that since it was on the same cylinder that it was possible that I had a bad ICM. There is two ICMs and they are the same. I figured that I would swap them and let the CEL come back. I was hoping that after swapping the ICMs around I would get a misfire code on a different cylinder proving that the ICM was bad. Well the CEL came back but its still P0302.
My question is what other conditions would cause a misfire on a specific cylinder? I am trying to wrap my head around this from a electronics point of view. what conditions triger this code in the ECU? I am open to suggestions at this point since most of the threads all talk about what I have tried so far.
02-17-2014, 06:42 AM
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I've talked to a few folks about this and apparently the coils that came from the factory do not throw enough voltage. My car does the exact same thing and the only true "fix" I've heard of is to do the TSi coil swap... It'll run you about $600 I think.
03-01-2014, 12:18 AM
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check out ecs, or 034 maybe, they have the tfsi coil swap with all wiring for like 350, thats the way to go, if that doesnt fix it, check wiring and compression check to make sure its all healthy
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