My 91 Deville wants to idle at 45 MPH. Have cleaned the throttle body, disconnected the cruise, turned off the AC with no change. Recently had codes E-70, and 22 which refer to the TPS as intermitent. I heard that it could be the Idle Speed Controller or the throttle position sensor but didn't want to spend the $ changing the wrong one. Any one had a similar problem?

Since it is an idle speed problem my money is on the ISC. I think the TPS would give you drivabilty problems.

Thanks, I'll try that first and see if it solves it. Will let you know.

Question first. Does it idle fast when it is cold or does that only start after the engine warms up? I had a bad oxygen sensor on a '89 DV that made the engine idle fast but only after it warmed up. The computer doesn't read the oxygen sensor voltage until the temperature sensor reaches operating voltage.