Honestly it depends on the kind of test that is used. Here in Arizona on my '97, all they did was hook up a scantool and check for stored codes in the computer. No sniffer, no visual inspection of the exhaust or engine bay. If they do any kind of computer testing (which they might not do on a '92), make sure your check engine light is not illuminated and you have no stored codes in the PCM.
If they use a sniffer, ensure that your catalytic converter is good by giving it a few solid raps and listening for rattles. Other than that, if your plugs, wires, ignition coils, and injectors are all functioning properly, you should be golden