Hello newbi here. I just bought 04 G35 coupe I have 300 / 327 codes. I’ve replaced plugs and 2 coil packs I verified by unplugging the other 4 coil packs that they are registering it’s still missing with the 300 code. far as the 327 knock sensor code I haven’t got too yet but would this cause the multiple misfire the knock sensor/harness? Please I need help thank you. Any suggestions would help.

 

Knock sensor is not related to misfires, the engine won't properly advance timing without the knock sensor signal so it will just feel fairly gutless. P0327 is USUALLY the knock sensor sub harness. It can be replaced without disassembling the plenum but it's difficult. You will probably want to take the plenum off, if you disconnect the throttle body you need to perform the TB closed position relearn, section EC - Engine Controls under "basic service procedures at the front of the manual.

https://www.nicoclub.com/infiniti-service-manuals

https://www.z1motorsports.com/z1-pro...ss-p-5833.html

Your P0300 random misfire can be tricky to find sometimes, did the plugs look normal? I would start by watching realtime data for the O2 sensors to make sure it is within spec and cycles properly. I would also do a compression test and a fuel pressure test (you will need a sandwich adapter like the one linked below). If all those tests look good and you're 100% confident there is no vacuum leak then start swapping out other coil packs for the two you replaced. What was the reason behind replacing 2 of your coil packs, was there some other codes it threw before?

https://www.z1motorsports.com/z1-pro...rt-p-9160.html