This is going to be a long post, so get your coffee ready
I have a 1996 Riviera 3800 supercharged. It was idling really low at times, usually after I had been driving it for a while, letting it sit for a bit, and went to start it again. Sometimes it would even stall. I did some research and decided to clean the IAC motor. Well, when I did this, I accidentally took off the TPS sensor. I put it back on - first wrong, and it was idling around 2500 RPM. I put it back on - maybe the wrong way still - I don't know. I broke the IAC motor so I went and bought a new one of those and put it on. Anyways - here is my problem now - that I have never had before messing with all of this: When I start the car, everything is normal. It idles perfect, runs like a champ. When I put the car in drive, everything seems normal until I am either hitting a certain RPM or MPH, and I can feel the car shift into another gear - 2nd or third. And it just stays there. There car doesn't shift. When I come to a stop - its like trying to take off in a stick shift in 3rd gear.
I unhooked the battery cables from the battery and touched them together to reset the computer after cleaning the throttle body where the IAC motor goes in and put the new IAC motor in.
I don't know what to do next. I don't know if I still don't have the TPS sensor in correctly or what. Tonight when I get home from work I was going to try unplugging the TPS sensor and driving it and seeing what happens.