[joshey]

short answer, yes i was wrong thanks for correcting me it is '94 on my druken mistake(i only have four down now) as for master tech, ha ha ha ha ha. my grandmother could look at a book for a few months and pass thoes tests. you know what my certs. are...inspectors lic. and nothing more, dont need them after all who give a shoot if r-12 has ance threads, the question is do you know the right way to charge the system, or are you connecting the bottle to the high pressure side and blowing your self up(oh yeah i am a/c cert too(this was taken from the test)) like i say its all book knowledge, i been working on cars trucks and bulldozers from 6yo on. OBD 1 is a name given to the first level of needed (clean air act of what ever the hell date it was) self-diagnostics that specifises that things that make emisions exceed the std be reported to driver in the form of a SES light OBD-1 also need to have a trouble code be stored that can be gotten by a service person. The other things required are some simple test features to acknowledge inputs from some of the sensors and an activation test that operates the items that the engine management operates (injectors, idle control valve, egr valve regulator).
(on most pre 94 buicks)

OBD-2 is a more elaborate requirement that requires any emissions critical part or function that the manufacturer can't assure will have ABSOLUTELY NO FAILURES to be tested.
OBD-2 has different levels and not all cars have as extensive an array of features.
ALL OBD-2 have misfire detection, cady converter monitoring, storage of certin sensor values and operating conditions at fault occurrence, and the capability to have the info retrieved by a scanner tool through a common digital language.
Further testing that is phased in and is on 100% as of 98 yr model (it might be 99 in some cases if the manufacturer earned credits that allowed it to delay [planting trees, dragging beached whales back to sea...... just kidding!!]) is the fuel tank vapor leakage test than many out there are very familiar with.