1998 Tacoma 2.7L TPS MIL problem

TPS trips the MIL when the engine warms up to around 140 to 150 Fahernheit. Engine must cool to close to ambient before the code (generic P0120) can be erased from the ECM. I tried:

- swapping out the TPS; no luck as the old TPS was within specs (now I have a spare)

- swapping out the ECT sensor (sic), as a local mechanic said that a common problem with TPS malfuctions on Fords were actually caused by a gunked up ECT sensor; he didn’t know if the same were true for Toyotas – it’s not, so I also have a spare ECT sensor (nuisance to extract, incidentally).



My next guess is the ECM itself (at $550 a pop).



Any other suggestions I should try first?



Thanks