They will usually give you a print out of what is wrong too...
I have a scan tool, but you're 1500 miles away...:/
You might check
www.j-body.org... Some cars - might not be GMs, but it's worth looking into maybe - you can hold in the trip odo reset and it will read off the stored codes. I know you could do this in my 2001 Grand Caravan.
I almost bought a new '02 Z24 4 door with a 5 speed...Kind of wish I had now. Rare car now since the 4 door Z was only offered one year. But it was red and i wanted black, plus it looked weird without dual exhaust outlets.