Having the same issue....factory boost control solenoid...factory injecrors...factory fuel pump...big 16g...full exhaust fmic greddy bov...tubular manifold...car wont rev past 4k...no boost leaks at all just checked...fresh plugs and wires..no clue what is causing this

This thread was so helpful to me...i completely understand now why my 16g and tubular manifold install basically killed my cars power....exhaust leak.....thanks for the info

I suggest also checking all your vacuum lines, I once had a 1g with similar issues and found that I had vacuum leaks on the lines that connected to the throttle body.