he did have a slight coolant leak that he says got corrected with addition of some additive to radiator. he tells me he does run it hard in lower gears once in a while to burn carbon off. yesterday we ordered the TPS, throttle body gasket and new hex bolts (original phillips on it now) and plans to have island mechanic install it for him even if the engine does not act up while in the shop. our approach is to replace inexpensive sensors leading up to the mass air sensor. i'll keep you informed of our progress. tks for your help.