i tampered with it before, and it didn't lower significantly.

 

This is to JayVee, who has an entirely different setup than the OP and really should have started his own thread about it. Anyway on a MPFI, when you take the intake off you will see there are two holes in the side of the throttle body before the throttle plate. The one on the back leads to the IACV and the one on the bottom leads to the FITV. Start the engine and see which one is drawing air.

If the FITV one is drawing air with the engine warmed up, FITV is bad.

If you block both side holes, the engine should stall. If it doesn't, there is an air leak somewhere else. Air leaking into the manifold from anywhere will cause the engine to idle too fast.

 

that was my next suggest, you beat me to it

 

sorry for the thread jack.!

thanks mk378.