Checked it out w/mechanic was told that it was carbon buildup on jets or converter. However, it did pass inspection. Could it be a bad sensor light?
We need the code to know anything. With a '92 you might be able to get it by shorting the correct two pins on the diagnostic connector and counting the light flashes. Any common manual will have that information.
The computer has much more specific information than “carbon buildup on jets or converter.” We need the specific error code that triggered the light. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here.