I have a 3.4 swap with a 340h running behind it not the f. It is a 3.4 swapp into an 88. Posted here since it will probably get more attention than the 3.4 swap section and is related to the 3rd gen drivetrain. Im getting a P0125 code. MAF, TPS, and both coolant sensors check out OK. On my obdII reader I am getting 0v for my o2 sensor. the voltage never changes. Tested the o2 and it is good. I did by it new. The connector to the o2 does read 12v with the car on and not running. So I know the o2 is getting voltage.

The thing is the torque converter is not locking up on my trans. Its not the break swith. The only thing that I think could be is the trans temp sensor. Mine is not hooked up because I never swapped the 340f sensor into it.

Has anyone had a trans temp sensor go bad on them??? If so any symtoms. If some is board I can give you an experiment. Unplug the trans temp sensor and let me know what happens.

I am concerned that the o2 sensor is not being seen by the obdII. I am skeptical of the trans temp sensor causing the issue but stranger things have happened with toyotas. Any ideas are welcomed.