So my 98 2500 Cheyenne has started doing something it had never done while in idle, it will randomly start revving on its own without any movement of the throttle. It will go to about 1500 rpm, slow back to normal idle, then spike again, with 0 input from me. While it’s randomly happening, I’ve noticed it mainly occurs when stopped at a light, or, when shifting from park into gear, both reverse and drive. Does anyone know what could be causing this? The only thing I can think of is the cold air filter I put on it is maybe confusing the MAF and the computer is getting a wrong reading? However I’ve had the filter since late March and haven’t had this problem until recently, it also isn’t doing it at all when going down the road, or revving it in park, only while the engine is idleing. Any ideas?