04 G35 coupe 6mt.

Alright, here goes. My car was misfiring, so I went ahead and changed the plugs (one was bad). I found oil in the spark plug tube so I took it to the dealer and they replaced the valve cover. Engine was still misfiring so I replaced the ignition coils where the bad spark plug was and where th oil leak was. Still misfiring and throwing no codes. Did a compression check and it was all good.

Took it to the dealer and the master tech looked at it for 2 days. He checked the fuel injection, intake, compression and spark and couldn't find anything wrong. They acknowledged that it was misfiring but said they couldn't find anything wrong and to bring it back when it gets worse or throws an error. My warranty is up in a few months. WTF do I do now?

 

They couldn't even pin down WHICH cylinder was misfiring?

 

No, when we were listening it sounded like it was randomly coming from either bank. Also, it wasn't throwing any code and the diagnostic tools weren't pinning it down either...