Throttle Position Sensor

Hi. I was adjusting my driver floormat last night because it got under the accelerator and caused a problem. Anyway, the van was ON but the engine was not running. I accidentally hit the accelerator several times in the process of doing this. Then, when I was ready to leave I started it up and the Service Engine Soon light came on. I took it to Auto Zone and they checked it out, and said I needed a throttle position sensor. I thought it may have just been from me accidentally hitting the accelerator. Anyway, I was curious and later hit it several times while the van was off. I started it up and the light hasn't come back on. Should I replace the sensor anyway? How important is it? Thanks

The TPS is a variable rheostat type sensor. It produces output voltages from .5 to 4.5V based on how much the gas pedal is depressed. The computer then knows (based on the output voltage) how much gas to inject into the engine.

Typically, these sensors fail by spiking voltage beyond the high limit (>4.5V) because of a dead spot in them or also can fail on the low side (<0.5V) (cut wire?). In the cases where the computer sees voltages out of range, it sets the CES light and tries to use "safe" values just to keep the engine running. Performance is shot and gas usage will go up.

You should keep an eye on the CES to see if it comes on again, and perhaps replace the sensor then. It sounds like your TPS does have a dead spot causing a spike, but more importantly, is that dead spot in your driving range of pedal travel which will interfer with driving.