Here are the specifics -

94 SE - 200K miles.

While driving, there is a surge under light throttle right at 1800 rpms. I can put it in drive, hold the brake (while stopped) and feather the throttle to about 1800 rpms (light load) and also get the surge.

Moderate to heavier throttle up to highway speed, no problems.

A few times it will die after letting off the gas when approaching a stop sign. It always restarts easily. Always idles fine.

CEL comes on and goes off after a surge. Sometimes it stays on until you restart the car, then it is off.

Carb cleaner through the throttle body. No change.

Codes? Here is the problem. I have tried two different readers (one at Advance and one at Autozone) and both say they can not communicate. Would this car be OBDI or OBDII?

I talked to a mechanic buddy of mine and he suggested the throttle position switch.

yours should be OBD I even though GM tested OBD II on pre 96 cars it was not commonly tested on pontiacs instead it was trialed mostly on caddys buicks and olds cars your car should be as simple as grounding the diagnostic terminal. the top right two terminals in the plug are ground and diagnostic once those terminals are jumped to one another turn the key to run your your cooling fans will click on and then your check engine light will flash count the flash sequence then refer to a hanes manual for diagnostic codes.

as for the surge yes i would agree the TPS but i would first check your CEL

Ok - here is what I found out. I had a friend use his scan tool (the car is OBD1) and the code was for the EGR valve. We disconnected the plug and the problems went away.

I was surprised as to how poorly the car would run, and even die. I didn't realize that the EGR valve could have such an affect.