What is a p0122 trouble code and what to do to fix it on a 1998 Chevy cavalier?

Answer 1

Test the Throttle Position Sensor. Just Google "How to test Throttle Position Sensor 1998 Cavalier". The code is for a TP sensor, Low Input. Try unplugging it and plugging it back up. Repair manuals walk you through the testing. Go here if you can. (an easy walkthrough)

The Throttle Position (TP) sensor is a potentiometer that provides a signal to the PCM that is directly proportional to the throttle plate position. The TP sensor is mounted on the side of the throttle body and is connected to the throttle plate shaft. The TP sensor monitors throttle plate movement and position, and transmits an appropriate electrical signal to the PCM. These signals are used by the PCM to adjust the air/fuel mixture, spark timing and EGR operation according to engine load at idle, part throttle, or full throttle. The TP sensor is not adjustable.

The TP sensor receives a 5 volt reference signal and a ground circuit from the PCM. A return signal circuit is connected to wiper that runs on a resistor internally on the sensor. The further the throttle is opened, the wiper moves along the resistor, at wide open throttle, the wiper essentially creates a loop between the reference signal and the signal return returning the full or nearly full 5 volt signal back to the PCM. At idle the signal return should be approximately 0.9 volts. You maybe starting to have trouble with the "wiper". maybe..... TP sensor is $30 @ AZ ....