my car idols like crap rpm goes up and down from 1000 to 2000 sometime even stay at 3000 is that cause of the tps sensor. if so i have a Ls throdbody and can i change the tps from the Ls to my GSR the one that has problems or is there something else besides the tps sensor

 

First it's called a throttle body If your idle is fluctuating, first check for vacuum leaks then clean your IACV. The TPS can go bad but chances are your problem is elsewhere. If it does turn out to be the TPS, yes you can use one from the LS on your GSR throttle body.

 

first of all thanks for corectin me and i checked alreqady for vacuum leaks and what is the iacv where is it located at

 

on the back of the intake manifold.