So I'm having a problem with the G35C 6MT, The car is running extremely rough and sounds / feels like not all of the cylinders may be firing - though it is slightly smoother at higher RPMs. I have straight pipes and something like this happened in the past and it turned out to be bad O2 sensors, however I don't think that is the case this time.
IIRC All of the issues happened at some point after the battery going dead, CEL is flashing, when I pull the codes I get O2 sensor errors however I have replaced the O2 sensors twice now (thought the first set may be bad) and installed the O2 extenders / fix just in case and still no dice. I then replaced all of the spark plugs and it was not any better. Moving down the list of what could be causing it I replaced the MAF and still same as before.
(Reset the ECU after each case)
Looking at different forums I'm coming up with camshaft or crankshaft sensors as other possible causes though I'm not getting CEL codes for them (that does not mean they are good though!)
After some reset cycles and running it sometimes it will drop the CEL, smooth out to run perfect for a few minutes and then drop back into running like s***. My thought on this is that whatever sensor is causing the issue gets back in spec long enough to get it running properly.
At this point I'm not going to just keep replacing parts - I need help. Ideas?
