Ok So a month or so ago I decided to pull my UIM and valve covers, paint and replace the gaskets. My car is idling high now but not all the time. It can as high as 2K, sit there and slowly go down. Other times it's cool and acts normal. I've noticed that if I get on it and then come to a stop she will sit at 1500 and slowly go down to 800-900 but even at that it's not ALL the time.

yesterday I pulled the throttlebody, replaced the gasket and cleaned the butterfly and everything (yes with cleaner ok for sensors). I've messed with the TPS sensor, and IACV plastic screw on top and nothing is changing. I've noticed in early morning (cooler outside) when I first drive her for the day is when the idle is up the highest.

This thing really has me stumped, it's not doing your normal vacuumn leak up high then down up high then down. I've checked all lines and they are connected and in the correct location.

Oh yeah, and no codes are throwing at all. The only thing I know is wrong with my car at the moment is when I was putting in my STS I broke a bolt on the Cat piping but can't tell by noise.

Any ideas or did this happen to any of you when you did this job?

 

if u are adjusting the screw and nothing is happening but u are idling high, it screams a problem with your IACV.

Test the IACV per FSM. And/or replace.

 

Try cleaning the IACV.

 

it should idle up high when you first start, but then drop down to lower rpm. check what the guys posted. are you sure you're not leaking thru the mani gasket? spray some carb around the gasket and lines and see if it changes the idle speed.

 

+1 for IACV

 

I'm going to replace the IACV gasket (as I reused it) and clean that. Then check the car to see if it's fixed. If not then I will try the carb cleaner method. I actually am hearing a hissing from the cat (which I said I wasn't in the OP). I'll just buy a test pipe that comes with new bolts and gaskets.