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:
Air distribution
The incoming air is distributed from a number of different vents in the passenger
compartment.
Air distribution is fully automatic in AUTO mode.
If desired, air distribution can be controlled ma ...
Suspension
The advanced, independent suspension system employs spring struts at the
front, the geometry of which has been carefully calculated to provide quick and
precise steering response, enhancing the ca ...
AUX
The AUX (auxiliary) port can be used to connect
a device such as an MP3 player.
Turn the SELECTOR control (see the illustration
on page 246) to choose AUX.
If the player is being charged throu ...
