How do states use OBD II for emission inspections?

Many states connect a computer directly to a vehicle's OBD II system. The inspector can then read "faults." In some states, this type of inspection has replaced the tailpipe emission test.
See also:
Safety
Volvos are renowned for their safety. This commitment is as old as the
company itself. As Assar Gabrielsson, one of the founders of Volvo, declared:
'Cars are driven by people. The guiding principle ...
Messages
When a warning, information or indicator symbol comes on, a corresponding message
appears on the information display. An error message is stored in a memory list
until the fault is rectified.
P ...
Interior design
'At only 4.26 metres long, the C30 is not a big car, but its spacious cabin
gives it a real big car feel,' says Mr Abrahamsson, Volvo C30 project director.
Volvo's iconic 'floating' centre console ...
