I did a lot of research on this forum, tuners, technicians and couldn't find a solution that worked.

First I tried swapping coils 3&4 but the error code stayed on Cylinder 3. Tried replacing the spark plug, no go. Was about to get a compression test on 3 (luckily for free from a friend), but I remember seeing Tobz Performance around where I was, called him up and he was nice enough to take me right then and there. He then fixed in about 10 minutes.

The problem was apparently my Fuel Pump relay went bad, but only for the high voltage part, so no boost worked fine, but boost was running super lean until misfire. Just my personal experience, hope it helps someone else out in the future.

Linky https://www.evolutionm.net/forums/ev...ay-1-test.html

 

Thanks for sharing! It helps when people state both their problems and what they did to fix it.

 

This is an interesting find, I am plague with P0300 code. I have checked everything except this. Hmmm