Car failed smog because of no communication. My car stereo was stollen. Does power get drawn from there? It's the only difference from last year.
OBD II communication failure on 1999 Hyundai Tiburon
Not all smog check machines are the same, and some have trouble talking to Hyundais. A helpful mechanic had heard of this problem and referred me to the State smog referee, where my car passed successfully. I even got my money back at the first smog place.
Check all your fuses.