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:
Temporary spare
The spare tire in your vehicle1 is called a "Temporary
Spare".
Recommended tire pressure (see the placard
on the B-pillar or on the fuel filler door) should
be maintained irrespective ...
Washing the car
The following points should be kept in mind when washing and cleaning the car:
The car should be washed at regular intervals since dirt, dust, insects
and tar spots adhere to the paint and may ...
Activating/deactivating warning signals
The collision warning system’s visual signals
are activated automatically when the engine is
started if the collision warning system is
switched on.
The audible warning signal can be activated/ ...
