Bob, Take my comments w/ a grain of salt, as I am not as familiar w/ the 20v engines in terms of symptoms. That said, have you checked the lower wastegate hose? The overboosting sounds like it could be the lower wastegate hose (well, on the 20v there is no upper hose). Check the throttle body hose and the lower intercooler hose as well. Taka '91 200q