I have a 2002 Cadillac Deville. Car reviving around 3000rpms before changing gears. I don’t have any codes, and no check engine light. I also have no idea…lol. I have cleaned my throttle body, but not the IAC. Would this have anything to do with the high rev. It’s been kind of cold around here lately it’s worse on colder days than others. Still high on warmer days but not as high as 3000rpm before it shifts. Anyone have any ideas what it could be? Is my transmission going bad?