tps relearn

[Ryridesmotox]

My buddy has an 07 Avalanche with a 5.3 in it. Been searching Google and the forums for the answer for about an hour. Can't find one I can wrap my head around...

He threw a P0121 code, completely stock, 130k miles on the motor. He replaced the tsp at the pedal and replaced he throttle body as well. His truck still hangs RPMs when you let off the gas.

How do I relearn the tps for him? I thought I could do it in the scanner so I don't have to burn credits. I found it in the on,off,% window but it won't relearn. Or do I need to do a whole CASE learn?

Any help would be ohenominal.
Thanks
Ryan

[mecanicman]

P0121 does not refer to a tps issue on that year vehicle. Its an airflow fault for a given position. It is most likely caused by a vacuum leak, but could also be a bad maf or map. Give the intake a thorough inspection for leaks. If you don't find anything monitor your maf and map readings with scanner.