What do they check on diagnostic port at pollution test places?

[Lee456]

Since I moved to Arizona when I've taken a car in for the pollution test they hook up to the diagnostic port instead of sticking a probe up the tailpipe. Does anyone know what parameters they look at to decide if you pass? It'll be a few years before I have to take the Speed3 in since they don't make you go for the first 4 years with a new car, but my wife will have to take her Focus in next year and I'd like to know what I could look at on the Dashhawk to determine if it will pass.

[bykeryder4life]

I think if they are using the obd2 port then you just cant have a cel or a pending one that keeps coming up and getting cleared. if they arent using the tailpipe it would be easy to pass....they really cant look into much of your exhaust thru the obd2 port, they might smell the fumes if the car is catless tho.

[wisniaPl]

in NY state they use obd2 you cant have cel...you will pas without cats just cant have cel...in other states they might require smog test and then you are fucked :P

[ThreeEdgedSword]

They're looking for any emissions faults as well as OBD Readiness Codes - which are designed to keep someone from clearing the fault memory and then trying to get it smogged before the code(s) set again.