Hi, I have a 2003 350z and when I start it when its cold it misfires really bad and does not idle. I have to hold the pedal at a position where it holds the revs so that the car warms up and when its warm it runs perfectly. I've changed plugs, coils, knock sensor and harness, maf, o2 sensors, injectors. The car has been sitting for a few years before I started working on it. The compression is good on all cylinders, and its throwing a p300 code. At this point in out of ideas, I need help.

 

did you end up figuring out what the issue was?