High Idle Problem!

I'm having a high idle problem sometimes when I start my Jeep. I thought that I had it fixed a week or so ago but I guess it came back. It did it when I first got it and a friend and I pulled the IAC and cleaned it and pulled the throttle body inlet tube off and sprayed throttle body cleaner in through the throttle body while the Jeep was running and it idled down just fine and was idling great. For days after that I'd start it up and it would idle just fine. I hadn't started it in 3-5 days prior to starting it today and I started it up and it was idling high! If I had to guess I'd say it was idling in the 2500-3000 RPM range. I went out to the garage and got some throttle body cleaner and brake cleaner and sprayed it down in the throttle body while the Jeep was running and it idled it down and it idled just fine after that. I can't figure out what the problem is. Also, I have a weird clanking noise coming from my Catalytic Converter. I wonder what that could be..

Try tapping on the cat housing with a rubber mallet. When the ceramic honeycomb breaks up it sounds really bad in the cat as it bounces around.

Any chance of a vacuum leak causing lean high idle? Check the throttle plate itself to see if the screws holding the plate are loose allowing the plate to shift and jam itself open.

my cables arent closing my throttle body all the way so check those too.