skn5002

iTrader: (2)

I have a 350z w/ STS turbo kit that has been running fine the past few years. However, a few weeks ago, I noticed my car to make more exhaust popping sounds. The p0300 was being thrown more frequently, but the car sounded and drove like normal. I assumed that the car was running richer and planned to have a retune soon. However, 3 days ago, I noticed the CEL light to flash constantly while casual driving . There was an abrupt change in the performance and sound of the car. It felt very sluggish, sounding like a WRX type motor. Idle is normal and remains constant, and there is no smoke coming out of the exhaust. The car is very sluggish though, and the CEL light constantly blinks while driving.

My car gave a p0306 code, indicating misfire on cylinder 6. I swapped the ignition coil packs with another set I had from a different motor, and changed all the spark plugs with new ones. However, the issue is still there and there are no improvements. After letting the car run for 30 mins or so with the new spark plugs, I pulled them out and saw that all the spark plugs were black except the cylinder 6 plug. The cylinder 6 plug remains clean and not dark like the others. What does this mean? Is the ignition bad on cylinder 6 or is the cylinder 6 injector stuck open? Thanks

Cylinder 6 plug is first on left below


Cylinder 6 plug is first on right below