Oi, this is an A3 thread. Get out S3 boy!
180bhp A3's were quattro only, and were not all ko3S either. Early ones were 180bhp from a ko3, later ones from a ko3S, changed around the same time as the FWD went from ko3-ko3S.
FWD's were 150bhp only, ko3 on early ko3S on late.
Your AGU is originally a ko3 engine as I'm sure you know. 6psi is around stock boost on ko3 and ko3S, and is where the actuator is set also, so it sounds like you're running on actuator pressure at the moment. This will not be 190bhp, or even close I'm afraid. 150-160 more likely.
Either the car is in limp mode causing it to revert back to actuator pressure, or there is a fault in the N75 system somewhere, either the valve is faulty, or something isn't plugged in properly.
It could also be, that it's not been mapped at all. Do you have any proof of the remap? if he's got a print out at 190bhp it sounds like it was mapped at some point, so I'd be looking for N75 issues first.