My KJ is throwing code p0123 TPS/ pedal position sensor

What does this mean?

I just got my KJ back from Jeep last week for a valve job.

Anyone??

"TPS" means "Throttle Position Sensor", cause of code as follows:

SymptomsSymptoms may include:
Rough idle
High idle
Surging

other symptoms may also be present
Causes
A code P0123 may mean that one or more of the following has happened:

TPS not mounted securely
TPS circuit short to ground or another wire
Faulty TPS
Damaged computer (PCM)
Possible SolutionsIf there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, carefully inspect all wiring and connectors that lead to the TPS. More than likely the problem is with the TPS wiring. Check the voltage at the TPS (refer to a service manual for your vehicle for this specific information). If the voltage spikes or is too high (over 4.65 volts with key on, engine off), then that is indicative of a problem. Carefully trace each wire from the TPS wiring harness to check for breaks, rubbing against other components, etc.