So I'm twin turbo fully built engine, turbos only have 1500 miles on them, out of the blue my car has been acting funny, won't go pass 5500 rpm in all gears. So first things first took al piping and checked for any holes for boost leaks came up negative, I also changed I couplers,so I replaced both wastegates, I replaced throttle body, and the coil packs still won't accelerate pass 5500rpm, the car pulls hard as crap all the way to 5500. My rev limiter is set to 7600 and I have 272 cams with Brian Crower springs and retainers, so initially I was thinking it could be valve float but I have Bc springs in retainers so I marked that off the list. My afr drops to 10.2 and my booost also drops, seem as if I'm losing spark and im hitting a flat wall at 5500 as if the Ecu is cutting everything, the car has no engine codes at all so that makes it a lot harder to diagnose the problem, I'm using a pmas maf sensor which support over 1000hp of air... Was wondering if any boosted guys has had this problem or similar

 

Did you do a re-learn on the throttle body after you replaced it? If not, that might be part of the issue....worth a shot anyway.

 

It was doing this before I replace throttle body... did every procedure, its not throttle body related