Hyundai Repair: 2003 Hyundai Tiburon Tuscani, hyundai tiburon tuscani, throttle position sensor

Question
Engine idles inconsistently.  Does not always return to idle rpm when gas pedal is released.  Also seems to do the same thing while driving.

Answer
I'd recommend primarily checking two items.

First check to see that there's enough slack in the throttle and cruise control cables to allow the throttle plate to close properly.

Presuming that's okay, I'd recommend checking to see whether the throttle position sensor (TPS) is giving any abnormal output.  Unfortunately, to do a good job of this, you'll need a scan tool which has the capability of graphing the output from the sensor, enabling you to look for any abnormal spikes in the readings while operating the throttle.  If you have a scan tool capable of numeric data readout only, you can try looking at the data while flexing the sensor back and forth where the connector attaches.  If this causes the reading to change significantly, you should replace the sensor.  If you're unable to do that either, you're probably limited to checking to see whether there are any TPS-related trouble codes stored, using your own code reader or taking the car to AutoZone or similar place that will read the codes for free.