Diagnostic Tools for '98 GM?

There is a company called B&B Electronics that manufactures and sells a product called the AutoTap. It adapts the OBDII port to a serial PC port. The cost is 300-600 depending on the model you get. I have one that works very well. You can look at and reset codes, as well as watch virtually all operating parameters in real time.

Found a few tools on ebay that look like alternatives to the main one available here. One, for instance, is called "Creader". Anyone have any experience with this unit?

thanks in advance

Autozone will read the codes for free, except in California where the car dealerships & big name repair shops got together to stop them from taking $150 of easy money away from them. It also prevents the customer from being empowered with knowledge. You can buy an Actron tester for $150 from them. Pays for itself the 2nd time..

I understand that there were a couple of issues WRT Autozone reading codes/resetting MILs in California.

1) They weren't CARB certified/licenced to do emissions repairs. (that's a state law thing, NOT a conspiracy by the repair shops) 2) They were erasing the freeze frame data, actually making it harder for the motorists to get a proper repair, i.e., the evidence needed to track down the failure(s) was being destroyed.

Hogwash. Anyone is free to take the time and effort to educate themselves.

Sure, if you know what you're looking at. Most won't.