TPS problem?

Have a 2001 Cavalier 4-Cyl. 2.2 Liter. Was driving to work and it felt like some hesitation now and then. Stopped at the light and pulled out then stalled. I started it up and was OK. Same thing on the way home. Engine light came on, put the scanner on and it said-TPS/A circuit low input. Would it be the TPS or can it be anything else?

It is most likely the TPS, although it could be in the wiring. To really check the TP sensor, you need a oscilliscope to check for glitches in the signal, a voltmeter will not catch them. So unless you have a scope, I'd probably just replace the sensor if there's no obvious damage to the wires.