Well, the car was running rich as hell at first, at some point it actually blew out the muffler. It was also running pretty rough. If I unplug the TPS, the car idles much better, and doesn't seem to be running rich any more. The car is an 88 GTA with the digital dash, but I'm pretty sure the check engine light isn't working. When I turn the key forward to run, I get no CEL, when I should get a code 12 (I think). Where is the CEL located on the digital cluster? I'm going to pull the cluster out and try to replace the bulb, but I'm not sure which one it is.

 

Should be able to see which one it is holding a light behind the cluster.

 

It's the one directly above the oil pressure scale.
The digital dash is a PITA to work with and has delicate parts. Don't rush. If you pull it, I would recommend changing all of the 20 year old bulbs if you plan to keep the car.
The vehicle info center can be a pain also. If it says "PONTIAC" when it boots up you're in good shape. IF you change a tail light bulb, change all of them with the same brand bulb. Just ask me how many hairs I pulled out on that one.
Congrats on getting a "rare bird" like mine.
And no, there is no way to get any of those buttons on the steering wheel to do anything useful...

 

Cool, I didn't think of that. Also, I'm pretty convinced that the TPS is the reason it's running so rich. I checked the voltage at the TPS, I was getting around .07v at closed throttle, and about 1.3v at WOT. Does this indicate a bad TPS? I also tried measuring the voltage coming from the TPS plug. I didn't see 5V there, only about .33V.

 

I believe you have to measure the 5V from the gray(+) wire to the black (-) wire at the plug with the key on. If you don't have 5V, you can stop there.
I have the factory schematics I can email you if it gets too deep.