shouldve mentioned that the engine usually revs to around 1.5-2k but sometimes as high as 2.5k in neuteral
+1 My car does the same thing, but only after nitrous runs. The throttle body need to be cleaned. It's a 10 minute job. Use carb cleaner and a very fine sandpaper around the butterfly opening.......The T/body gets dirty and the butter fly sticks and the IAC motor can get dirty and stick also. They claim you can't clean them but I have many times.