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:
Blocking access to the trunk
Normal locking/unlocking function
Locking/unlocking points with valet locking activated
By utilizing the remote key with the key blade removed, the valet locking feature
enables you to block a ...
Disabling the passenger's side front airbag
Volvo recommends that ALL occupants (adults
and children) shorter than 4 feet 7 inches
(140 cm) be seated in the back seat of any
vehicle with a front passenger side airbag, and
be properly re ...
Engine specifications
Charge air cooler (Intercooler)
Turbocharged engines employ a turbo-compressor
to force air into the engine inlet manifold
and a charge air cooler to cool the compressed
inlet air. The resulting ...
