Looking for some help if anyone can. My 05 Dakota has had the engine surging for a couple weeks now. Generally more so once warmed up, rather than immediately on start-up. Will randomly go from 700-1200 rpm, especially when idling in park. Once into gear, it won't do it as often (but still does occasionally) and I'm certain it does it on the road too. In fact, yesterday, my transmission shifted down to 3rd and back up to 5th on flat terrain repeatledly. I also had no power trying to pull into a parking lot uphill. I put it in reverse and then back into drive and seemed to work fine. Anyway, a year ago the EGR valve was replaced and recently they cleaned out the throttle body hoping that was my problem, but it did not solve it. There is no engine light on and the guy told me he can't figure anything out without the engine light on. Someone else told me it was a vacuum leak, but he couldn't find it and another mechanic said no vacuum leak. I have since replaced the TPS and IACV thinking either of these could/would solve my problem. I have unhooked the battery to try and reset the computer, which also did nothing. Any ideas???