Washoe, Clark, and apparently Nye in Nevada do the opacity test. It's a joke. It is totally dependant on how hard the tester romps on the go pedal. If he eases into it, no problem. Even on my lightly modded 97, you could romp on it and be OK. Passing was under 20 or 30 or something. Mine was under 1. Another way to suck $$$ out of our pockets. If it's that big a deal, all vehicles should get smogged everywhere. If it's not a big deal, leave us alone!