I've got a 2007 A4 with the 3.2 liter. Tiptronic 6spd transmissions and have been dealing with very infrequent flashing EPC/CELs. It only happens once every 500+ miles at what seems are the most random times.

It does throw a P0302 (cyl 2 misfire) but is a "pending code" and doesn't result in a persistent CEL, ie; the car goes nuts, limping and misfiring. I pull over, stop and turn off the car for a minute, turn it back on and all seems normal again, including no CEL.

I pull the codes and get a stored/pending P0302 every time.

I've tried replacing the spark plugs (all of them) and I replaced the cyl 2 coil pack and thought the issue was resolved after the coil pack, however it occurred again last night.

I don't know what else could be causing a cyl 2 misfire. A bad ECU? Wire from ECU to coil pack, or injector? I can't think of anything else.

Anyone have any experience with this or suggestions? Anything would be greatly appreciated.

 

I'm an idiot. That should be EPC not TPMS light...

Nothing to do with tire pressure.

 

Might try swapping the coils for cyl 2 with another cyl and see if it happens again and the CEL changes to that cyl. I would have suggested replacing the coils as a possibility, but you already did that. If the error moves than maybe the coil is bad again.

 

Turns out this was in cyl 2 (on top of the valve). Must have fallen in there while someone was working on it or via the intake manifold?

Is this even a part of the engine on these cars??

After removing the car seems to run fine.

 

Not sure what that is. If you are close to an Audi (or VW) dealer you might run by there and show it to a mechanic. Odd that it was just sitting in there. I would identify it just to make sure there isn't something missing in your engine now that might cause issues later.