Originally Posted by initialgemini (Post 712790)

They don't stop all vehicles. I've been through a couple of them when I had a boosted hatch back; but not as of recently. What they look for are "gross polluter" which are cars that have faulty or missing smog equipment. Usually when I pass by, they target older cars or cars that look heavily modified.

Usually its just a quick visual inspection of smog equipment; however, if they have something to suspect, they'll do a quick sniffer test right there. What they'll do is attach this probe to the end of your exhaust and hold your car idle above 3K and evaluate the emissions.

I wouldn't be too worried if you had high flow cats; since technically they are still functional Catalytic converters. If you have test pipes, after market turbo kit, or have a lot of exterior modification I would be weary.