Another Dreaded PO300 Thread

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Hello everyone, it's been years since I posted on the forums but don't know where to go next with my car. I have a variety of other threads on this topic, so mods feel free to reprimand me if I am beating a dead horse.

2011 370z sport mt, factory engine apart from K&N filters, 105,xxx miles. Routine maintenance regularly and new spark plugs ~10,000mi ago.

In January 2020 when the weather got cold, after a 3 hour drive my car started throwing a PO300 code and the ECU would raise the idle slightly otherwise driveability was fine. I the code multiple times with my OBDII reader but it would come back on soon thereafter. At that time, I also installed a new clutch and flywheel. No other codes were being shown. After about a month I took it to the local dealership where they read then turned off the code and it stayed off until January 2021 when it shows the same symptoms.

I have since had the injectors bench tested/cleaned, cleaned MAFS, done a compression test, done a smoke test, sprayed the running engine with starter fluid to find leaks and the CEL continues to come back on. I have now had the car to Nissan four separate times and the codes they pull will show either an unspecified misfire; a misfire on bank 1 or a misfire on bank 2. They also performed a "fuel system service" which is I guess something they recommended. At the same time, once they reset the CEL, they say everything seems to be running well and within a few days of leaving the dealership the light comes back on.

Anyways, as of today my car won't pass state inspection and registration is coming due so it looks like I have a nice nissan paperweight. Looking for recommendations. Otherwise the next step I guess is to start throwing parts at the car (fuel pump, 4x O2 sensors, knock sensors, cam sensors etc) or pull the head. I can also repeat a leakdown test to see if anything has changed, but don't have air at my house.

oof. I was hoping my car would just last until the 400Z came out and I could rid myself of it.

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