Re: Help with TPS replacement (P0123/0121)
The IAC stepper motor sits under the TPS on the throttle body (see attached picture). You can easily remove the IAC motor and clean the plunjer, but the idle air canal will be dirty as well. Best is to remove the resonator box and then, while idling, spray some carburator cleaner through the idle air passage (the half moon shaped opening under the main air canal). Do it bit by bit to not stall the engine. The IAC motor should be installed to do this procedure.
You also could remove the whole throttle body and clean it out completely, but this is a lot more time consuming.