98 qx4 downshifting from overdrive TPS or trans temp sensor

[ipeelscats]

Today my 98 QX4 started to downshift from overdrive when I released the throttle while cruising. If I put my foot back on the gas, it shifts back to OD with no issue. The issue is random but frequent. The trans seems to shift fine but it keeps jumping in and out of overdrive. I have been reading about similar issues and wanted some opinions. Should I try to clean the throttle body (about 1yr since done last)? Should I replace the TPS or trans temp sensors?

[ipeelscats]

The problem seems to also happen at lower speeds. I was doing 20 in my neighborhood this morning and when I released the pedal the rpms went up and it tried to downshift. I am going to clean out the throttle body again when the engine cools down.

[ipeelscats]

Throttle body cleaned. The cleaning seemed to alleviate the problem for about an hour. Seems like the tps is the culprit.

[ipeelscats]

The sensor finally threw some codes. The truck does not want to change gears. 4wd and cel lights are on, OD light flashing.
P0325 - Knock sensor 1 circuit
P0120 - Throttle position/Pedal position sensor/switch A circuit
P1705 - Throttle position sensor circuit A/T
P0510 - Closed throttle position switch
New OEM sensor is in the mail.

[atraudes]

Check out the one-man thread Sorry no one was able to pitch in with some help, but it sounds like you nailed it! Thanks for posting back with your findings!

[ipeelscats]

I received and installed the new tps today. The truck runs like new again. Victory is mine.