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:
Sensors
The sunlight sensor on the dashboard and passenger
compartment temperature sensor in
the ECC control panel should not be covered
in any way as this could cause incorrect information
to be sent to ...
Queue Assist*
The following functions are linked to your vehicle's automatic transmission and
comprise the Queue Assist feature.
Please note that the lowest speed that can be set is 18 mph (30 km/h), althoug ...
Park position (P)
Select the P position when starting or parking.
Shiftlock
When P has been selected, the transmission is mechanically blocked in this position.
The brake pedal must be depressed and the ignition mu ...
