2005 Chevrolet Impala 3.4L Engine P0121 Code: Throttle Position Sensor Issue and Hesitation After Replacement
My 2005 Chevrolet Impala with a 3.4L engine has been displaying the P0121 diagnostic trouble code, which indicates an issue with the throttle position sensor (TPS). I replaced the TPS sensor as recommended, but the check engine light remains on and the vehicle still hesitates during acceleration. I'm looking for advice on troubleshooting this persistent problem. Any insights into possible underlying causes or additional checks would be greatly appreciated.
Did you verify the 5V reference, ground, and signal voltages at the TPS connector? Please observe these voltage readings as the throttle is gradually opened. Additionally, ensure your code reader displays all stored codes, including manufacturer-specific ones such as P163x — these may provide further insight into the root cause of the P0121 issue.