I have a 92 f150 that idols bad and misses especially at low speeds and idol. I did the self test and got code 538-operator error, 536-brake on off faliure and 632- overdrive cancle switch changing states. Can any one tell me what i need to fix and how it is affecting the truck running bad?
Thanks

 

Moved to proper forum. Email off

 

The codes you got don't have anything to do with the problem you described. When pulling codes, I believe you need to hit the brake pedal once, and engage/dis-engage the OD. That's why you got those 2 codes.

Regarding the problem you described, it sounds like it could be vacuum or spark related. You might want to start with a tune up... plugs, wires, and fuel filter.