No chips that I know of.
As far as tools go, most sensors are replaceable with basically a wrench. Do you at least have access to an autoparts store if you need to replace basic parts? If not, just leave the air off and bake.
Does your A/C work well? It's possible that your pump is starting to seize up and is really straining the engine. My wife's Probe did the same sort of thing.
I'm headed home right now. Look for some wire or something that you could use to jumper connectors with. We'll get that code. Since the check engine light went on as soon as your A/C went on, it's a good bet that the computer has the answer. Do you have a cell phone? Maybe I could call you while you're at your car. If you do, send me a private message with it. I should be home in about 40 minutes. If not, do you have access to an IRC client?
------------------
351W 89 Mustang GT Convertible