My mech today installed a new CPS. He (and my previous mech) told me the ignition switch was starting to go bad so i went over to autozone and picked up one for $30 and put it in, no problem. Well i have noticed my idle is a bit higher now--and it stays higher longer. Previously when i let off the gas the rpms would immediately drop but now it stays at the same level for a second or two after letting off. I don't know if this is good/bad, normal or not. Any explanations?

 

In for replies...I have the same problem, I think. Unless you are saying if you tach to say 3000 rpm, let off gas and RPM stays at 3000 for 1-2 seconds then drops to normal idle level My problem is when I come to a stop, Idle sits at 800-900 for 1-2 seconds, then drops to 650. Not a huge issue to me, but since you started a thread, lets see what we come up with.

 

I have the problem similar to you. OP, you need to state numbers so that we can help you further.

 

I actually have noticed both of these things...
I don't remember the exact numbers, but if i recall i would accelerate up to around 1500 rpms--then when i let off the throttle the tach remained right at 1500. However it didn't feel like i was still accelerating further so i don't think it was just the throttle plate getting stuck open or something. Perhaps it is just an error with the tachometer.
But I have also noticed this at idle as you described--coming to a stop it will hang around 900ish, then drop to right around 6-700. Of course, sometimes my rpms drop out completely at this point and the car will stall, but i dunno if that's ignition switch related or not (Though Autozone's "faulty ignition switch symptoms" blurb said it was, however trustworthy that is).

 

Unlikely to be the ignition switch; more likely an IAC issue; try cleaning it and see if that helps.