i believe the only one with a vnt turbo was a 150 hp ..am i rite ?
if so the problem may be just sticking vains ..check the maf sensor also ..if it feels like there is a sudden loss of power this could be the issue.
by the way a golf with 130 k on it will feel absolutly no different that one with 30 k on it..the only way to tell the difference is by the odometer reading ! :D