P0121 GMC -

Question

Replaced the tps on the throttle body and the engine warning light remains on. I can clear the code it will stay off for a few cycles but then returns. connectors are clean

Answer 1

Hi there,

Another possible cause is the ECM. Here is some more info for you.

P0121 GMC - Throttle Position Sensor 1 Performance

Read more: https://www.autocodes.com/p0121_gmc.html