I would clean inside the throttle body with cleaner and a tooth brush, clean all carbon from the butterfly area. If it still idles high clean the IAC valve.
Been having an issue lately with my 3.8 LS running high RPM's at idle. Without me touching the gas, the car takes off on its own when I let off the brake. I'm thinking that the throttle is stuck open a bit, but it's going to be this weekend before I get a chance to look at it. Any advise on what to look for, or what else it could be before I get my hands dirty?
So just an update, the issue seemed to go away on it's own. I went ahead and changed the PCV valve and associated parts with the AC Delco kit. After a few months without an issue, it happened again the other day, but hasn't happened since. Once I get some time and it quits raining, I'll look into it some more. Thanks for the tips!