A little history....
Car had a loose battery terminal and the lights started flickering and the engine ran rough.
Have a Maxscan GS500 so I can read and erase codes.
Fixed the battery terminal issue and the service engine light came on and the idle was surging up and down in a cyclical fashion.
Read the codes...P0122 Low TPS voltage, P0171 system too lean bank one. Also had an O2 sensor code (can't remember the number).
So I purchased a new O2 sensor....changed the upstream sensor near the radiator and that code didn't reset after I cleared all codes, the TPS code was still there and the check engine light reset.
So I changed the TPS.....no change, after code erase, TPS low voltage code came back.
So I tried pulling the battery terminal and putting it back on and then driving the vehicle to relearn the PCM fuel trim.....same code still showing P0122.
Put the old TPS back in.
Looked at my service manuals. Went through the P0122 service check procedure. Checked ohms on the TPS, OK. Checked voltage on connector after removal with key in on position. Voltage OK. Then took PCM out and backprobed connector with Ohm meter to verify connection back to TPS. Both check out. Only one left was to check connector A28 which is a gang connector. Took awhile to get to it in the wire loom under the fuse box. Pulled each of the three connector bars apart and tey wrere all gooped up real good with white dielectric grease....assume they were OK.
Still have the code and surging idle!
Any advise would be helpfull because only other item in the service procedure is to change out the PCM
