I had a very similar problem in an '86 Thunderbird--high idle, car running away--and a good cleaning and lubrication of the idle speed control solved the problem for years until I sold. Not sure if there is any similarity between the controls, but a good cleaning and lube rarely hurts anything that moves...
As to your other codes it sounds like your A/C charge is low (probably not working) and that the "Air Bag" service warning bulb may be burned out.
ht tp ://ww w . you tube. com /watch?v=qC1Omt5_ ItM
The forum won't let me post links yet. Take out the spaces in the link and there is a video to show you how to test it.
I'm not sure your 92 is the same as my 95 but there is a video I used to test mine. The 2nd one they show is what mine looks like.
When you put it back on the car connect the 9 volt battery to the 2 terminals to run the plunger all the way back in. Install it and check the gap between the plunger and accelerator, I think it should be .30 if I remember, someone else can verify this. You make have to turn the bolt on the plunger in or out to get this.
My car was doing the same thing and it turned out to be a bad throttle position sensor. Again I'm not sure your 92 Seville is the same as my 95.
I was just taking a look at the ISC, I didn't test it, no jumper cables. But I did notice I would like grinding noise it almost sounds like it's spinning and it's making contact with the walls. And when I shut the engine off, it keeped on going. Now I know it's a motor, but I dont think that loud grinding noise is normal. Is that the cause of the high idle?
I would like to thank everyone for taking the time and helping, I will pay it forward. @stevillests thx, that video. I did exactly what was on it, and yes its the ISC. @ranger yes the plunger was in contact with the throttle hammer and would not disengage or engage. Again thx for the help.