A few years back they used to have portable infra/red smog machines strategically placed on on ramps so once you saw them you could not turn around. If it failed you got a notice to go to emissions or have your registration revolked. The bad thing is most people would let off by the machine and the HCs would go through the roof. Havent seen them for a while though but used to suck

 

i drive alot since im a field mechanic.

i have seen them all , although not in about a year.

most common is freeway blind interchange's . so when you follow the signs and circle around you go through the little sniffer setup they have on the side of the lane with a van and cameras all setup . its sense's your exhaust and if it see's more polution than normal they send you a notification in the mail to get a mandatory smog .

the other i see is usually on a semi main street where they have survey crew construction signs . all looks normal until you pass the first van then you see a higway patrol with a dyno setup and they pull in random vehicles for a test.

like the wise trevorator said , our trucks usually arent profiled. however im sure they would second guess mine with the loud exhaust/looks it has . luckily its awd and would roll right off of the dyno .

its weird i havent seen them in a good while . probably downsized that program once the econmony went sour.

 

how do you get away with this? my mom lives in washington and i was wanting to do it.

 

Thats ridiculous.. I dont care whats in cali, warm weather, water, mountains, if they pulled that kind of crap wherever i lived id be outta there really fast.