Hi guys-- I have an 82 Trans Am with the Cross Fire Injection. Lately, I've been getting a Code 43 (ESC Control Problem) and have noticed the motor hesitating a bit, but only when warm. Here's what happens: car runs great when cold, no hesitation, great pickup. When warm, the car still runs good, but seems to have lost some power and hesitates from a stand still. I only get the Code 43 when warm. I've replaced the o2 sensor, EGR, MAP, plugs, wires, cap & rotor, and ignition module (under the distributor). I noticed the problem after I replaced the old EGR valve, which was stuck closed. One question I have, could this problem be caused by my use of premium fuel? I've heard that the ECM will try and advance timing until it hears spark knock, but since my EGR works properly, my timing is stock, and I'm running premium, will it ever hear spark knock? Also, how in the world can I remove the knock sensor given that it's probably all but glued into the block? Car does only have 30,000 original miles on the clock and the engine is tight and noise free.

Fuel should not have anything to do with it...especially premium. You don't want spark knock, so if you aren't getting knock then that is good. If the ECM senses knock it will retard timing until the knock is gone. Regardless, you are getting a code 43 so you either have a faulty knock sensor, faulty ESC controller, or faulty ECM. I have the diagnostic flow chart if you need it.

Do you know where the ESC Controller is located? Under the dash by the ECM?

I believe it is under the dash...I'll have to check my manual and get back with you.

If you have to replace your knock sensor, make sure the coolant passage is clear behind it. I had an ignition code that was intermittent and ended up being crud behind the knock sensor not letting it read accurately.