When a shop does an emissions test on a vehicle, do they actually measure what comes out of the exhaust? I heard a couplpe months ago about adjusting air/fuel ratios to pass. Is this because of an ecu test or something? Any help is appreciated.

 

I don't know about PA, but they do measure the tailpipe in CA as well as your ECU if its OBD2.

 

http://www.dep.state.pa.us/aq_...t.htm

 

they wont smog your car with anything to change air/fuel ratio on it...
at least i dont think so in california

 

Thanks guys for the help.

 

no prob...good luck just be glad you dont have a cali smog to do