Hello, I recently bought a 1997 legacy rs that had a single turbo sti motor swapped in and it doesn't go past 4k rpm it's almost like hitting a wall and it won't climb in rpm. Until that rpm it boosts to around 5 or 6 psi and feels normal. Even when going down a steep hill it will not climb but still stutters away as if it's starving of fuel or lack of spark, done spark plugs, coil and apart from fuel pump I don't know what else It could be? Maf? I've tested for boost leaks but seems to be completely fine, idles a little funny but not horrible, won't hesitate when revving out of gear but as soon as there's a load on the engine it won't climb rpm. Any ideas?
Set the title to wrx only because it's a wrx sti motor and that's what I'm having trouble with. It's a v4 motor for those wondering
Can post video of problem
Cheers
