Okay, here's the deal. I just redid all the vacuum lines to make sure nothing is leaking. When the vacuum line is connected to the wastegate, the car "holds" boost, according to the gauge, but runs like crap. If we disconnect the wastegate vacuum hose, and run the car roughly at 1/2 throttle to keep boost around 8psi, the car runs awesome! There are no engine codes. Any ideas on what it could be?
H22 turbo.