1st is there a fault code for the TPS? If not have you checked the ohm's to see if it's in spec?
Does the tps click while closing? Have you checked your spark plugs? Assuming they are the stock f5dpor how old are they? Is the car chipped if so how much boost are your producing?
Anything higher than 22psi on the 2.5 PT is not good.
HTH's Austin