There are reasons for the Bureau of Automotive Repair to be concerned about fraud at test and repair facilities, as indicated by differences in test results when the data from both types of stations - test/repair and test only is compared and analyzed.

Fraud can be in the form of overlooking missing emission control equipment that would be an automatic failure (even if the car passes the tailpipe cut points) or using a "shill" - testing a known clean car in place of the actual car that requires testing, and such fraud is usually financed by a bribe to the test tech by the owner. Another common fraud is manipulating the test to make the car fail and then selling the owner "repairs". This is easy to do by beginning the test before the car is fully warmed up.

Licensed emission test technicians face fines of up to $10,000 and loss of their license for engaging in fraud.

More and more facilities are test only, and the fewer test and repair facilities are being more closely scrutinized by the BAR.

I personally find that the test only drive thru facilities are the most convenient to use. They run the test while you wait and watch in about the same time it takes to run a car through a car wash. Also, they have no financial incentive to fail your car, but like most automotive service operations, the competence of the techs varies widely.

Duke