I have a really bad misfire in my 2002 subaru wrx.
I have had the car for about a year now.
it has 91000 miles on it.
HKS turbo back exhaust
Turbo Xs FMIC
HKS type s bov
turbo xs short ram intake
COBB accessport V2
Ok so here is my story,
I got this car stock from a dealership with 80,000.
I started to add modifications to the car. I got a 20G turbo with a 800cc injectors setup, high flow up pipe, and a COBB pro tune from alige automotive in maryland. Took the car home for the first day after everything was completed. I was breaking the car in, running around 17-18 PSI. Everything seemed to me working fine. Steady boost, Clean acceleration, no problems whatsoever. After about an hour of me toying with the new setup, the car starts to misfire, BADLY. So i decided to turn the boost down to a safe 10psi. The car ran great, normally. But now when i take the boost over 10 psi it misfires and stutters BADLY! The check engine light blinks, and throws 4 codes. 1,2,3 and 4 cylinders misfire code. I can take the car back under 10 PSI and it will run perfectly, even at redline. I took it to the dealership and they had no idea. They said they couldn't help me because of all the modifications i had done. I checked everything, to spark plugs, vacuum leaks, MAF, the pro tune, i even changed the MAF and cleaned out my inter cooler & piping. Changed spark plugs, Checked the spark plug gaps. I DID EVERYTHING I COULD POSSIBLY THINK OF! I tried running 103 octane. Still nothing. I'm going crazy.
OK so here is the funny part.
I'm pretty good with automotive mechanics & turboed cars,
So i decided to take everything off and change it back to stock. Since i still had all of the stock parts and could do all the labor myself. So i put the TDO-4 stock wrx turbo back on, and the stock 465cc blue injectors, and the stock cobb accessport map. AND THE CAR DOES THE SAME THING! It will run perfectly under 10 PSI but when i take it over 10, It misfires and stutters BADLY.. Im ready to give the car back, i cant take it.
IF ANYONE CAN THINK OF ANYTHING! PLEASE REPLY TO THIS POST!
IM BEGGING YOU GUYS FOR HELP!