As I have a electronics repair background (Army), I know if its a potentiometer that has gone bad the part can't be much. If all I need to do is get to the manifold I will attempt to do the repair myself.
My reason for suspecting the TA is my ASR light stays on without any noticed abnormal ASR behavior. I only get a code 5 on the computer and resetting only lasts about 1-2 days depending on how aggressive I am with the throttle. The car has already had the TA replaced by the PO 5 years ago?