Impala 2001 Throttle Position Sensor!

The Innova scantool will only read codes that set the CEL. These are called hard codes. The TPS may have set a soft code, one that doesn't set the CEL. Take it to a shop or parts store that will read all codes for free.

In California, Pep Boys and Autozone used to, but a new law was passed recently making it illegal. There are numerous small repair shops that will do it for free. Aamco advertises that they scan for codes for free, also.

With a fuel injected vehicle, the throttle pedal doesn't control the amount of fuel entering the engine, it controls the amount of air. So, if you have to move the pedal around while starting, this tells me the engine is getting too much fuel during the startup process. This could be a leaking injector, or the computer receiving incorrect signals causing it to give more fuel, or processing the signals incorrectly. This means there is a possibility the problem is the throttle position sensor, but it could also be a bad manifold absolute pressure sensor/mass airflow sensor, oxygen sensor, or other related sensors.