I'm Thinking, and i know how much of a pain in the Rear end it could be. But it would be usefull....

Maybe Get a sticky of the Gen I Obd codes for Buick, or a link for it?
And the same for Gen II Obd..... Cept i think that might be better off as a link, theres like 2000000 million codes. And yeah.. I Probally should post this in the non specific Forum.... But its just an idea.
Bill

I can't speak for odb-i codes but for odb-ii here's a link that may be helpful for GM cars.

http://service.gm.com/gmspo/mode6/