Where is the throttle body sensor that has two prongs and is round on a 1990 Cadillac DeVille?
It is at the rear, passenger side, of the throttle body. It is also three prongs. -L
It is to the left and slightly down of your throttle body. Follow your air filter box all the way to the throttle body and to the left of that on the block is the sensor you can not miss it their is wire clipped on top of it. If you unclasp that wire you will see three prongs and that is your sensor/switch. Very easy to replace.