Saturn Vehicle P0122 and P0133 Diagnostic Guide: Fix for Rough Idle and Oxygen Sensor Issues
I've identified what the OBD2 codes P0122 and P0133 mean, but I'm still unsure how to resolve them. After replacing the Throttle Position Sensor (TPS) last summer due to high idle issues, my Saturn vehicle now exhibits a rough idle—around 75-800 RPM when in gear—and slightly rough idling at approximately 1000 RPM in park. The P0133 code related to the oxygen sensor is particularly confusing as I have no clear idea of how to address it. Any insights or step-by-step troubleshooting tips would be greatly appreciated.
Verify the TPS signal and its electrical circuit, as well as the oxygen sensor circuit integrity—faulty connections or weak signals can trigger both P0122 and P0133 codes.