first off let me say that i know a pretty good amount about cars, turbos, engines and such... however as most of you know- subarus are alittle bit different animals then the rest haha.
last month a friend of mine purchased an 03 sonic yellow wrx sedan. its in pretty good shape and only has 65k miles on it
heres the issue:
the car has some modifications done to it and it seems like the more i get into it, the more i find. heres a list of what iv found so far:
larger turbo- looks to be vf39 from an sti but im not sure
3" down pipe
samco sport intake pipe and hoses
perrin boost control soliniod
turbo xs utec engine managment
lots of suspension mods as well.
my friend wants the car to be much closer to stock and to be very reliable. my thought is to let the factory ecu handle the tune and leave some of the aftermarket parts on, as this would make it more reliable i would think. so i have plugged the factory ecu back in and put the stock boost control soliniod back on and reran and routed all the hoses back to factory. the cars idles and runs fine until you load it up enough and get into boost- heres where i have the issue...
the car misfires or shudders until you let your foot off.
it seems to be the worst in lower gears and happens at about 4k rpm but as i said it depends on the load and higher boost levels.
the check engine light does not come on.
i disconnected the battery all night to reset the ecu and still get the same issue
i guess my questions is does anyone know what i should check or replace next? is this a fairly common problem or not? i dont really have the money to take it somewhere and given the mods on the car, im guessing alot of shops wouldnt touch it anyway.
any help would be greatly appriciated