Need some help!
My car started to misfire, the next day it stopped then it came back. At the beginning it was only cylinder 4 and now it's all of them. Tested coil packs change plugs, new fuel filter, compression test=155-150 on all four, new silicone piping (turbo inlet perrin. Intercooler piping mishimoto) .
When the car is cold it's not rough idling and no misfire. when it starts boosting it's start to misfire. When not boosting there's no misfire. No turbo leaks.
Sorry for my bad english😊

 

definitely check your spark plug gaps

 

Gapped plug to 0.28