Code Reader for a 2000 Tahoe Z71

Where can I get a code reader for my 2000 Z71. How much do they run?

I know AutoZone does it for free however the service engine light must be on for them to read it. The last time I drove over there to get it read, the light went off!

I don't know if your still looking for a code reader(OBDII type), but I got mine for my 2001 on sale at Schuck's for $99. They are just like a Autozone if you are not familiar with them. I think it's worth the investment if you are going to mess around with the truck yourself. It will reset the computer and do a system check also. Get the Haynes repair manual for the codes and repair help. Chilton's bought them out, but the 2000 Tahoe is available online if necessary.