Joe, OBD1 started in the 80's. If a car could set a check engine light, or store a code back then, it was OBD1. Legion is dead on, everybody had it, but it was different for all makes. Sometimes it was different from model to model within the same Mfgr!
OBD2 is a standardization protocol. All vehicles sold in the U.S. had to conform to that protocol.
Most of the real scan tools (not just scanners, there is a difference) will do OBD1, but it is car Mfgr specific. So each car Mfgr has a special interface cable for the scan tool.
I plan on replacing my old one with this one soon:
http://www.autoxray.com/product_detail.php?pid=94
The one I have now is so old, they don't list it on the site any longer.
Just in case everyone doesn't know, OBD stands for On Board Diagnostic.
Rick: There is a reason that O2 sensor is reading lean. Might be a bad sensor, might be an intake gasket leaking, might be a clogged injector, leaking fuel rail, bad wiring harness, or a whole slew of other things. The problem could even be on the other bank of cylinders, and the ECM is trying to cut the fuel back to keep the other side in check. See what I mean by being able to look at all the other sensor data? If you can "see" what the computer "sees" you can usually tell what it is trying to do. It's just a computer, and a "dumb" one at that. It's just REALLY fast. It has a set of "maps" in it, and if the data goes off the map, it throws out the Check Engine Light. It doesn't care why that sensor went off the map, just that it did.
If the car wasn't running, and they turned it over by hand and it showed a rich reading, it sounds like you have a leaky injector. Unless the ECM is telling an injector to fire, it should be closed, and not leaking any fuel into the intake port to give you a rich reading. Injectors are set up so that fuel pressure helps close them ( they open AGAINST fuel flow).
Of course it's hard to diagnose a car in Va. when I'm in Il.
Once again sorry for all of the words, I'll shut up now that I've put more than my 2 cents in!