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:
Fastening a seat belt
Buckling
Pull the belt out far enough to insert the latch
plate into the receptacle until a distinct click is
heard. The seat belt retractor is normally
"unlocked" and you can move fr ...
Removing the remote key
The remote key can be removed from the ignition
slot by pulling it out. ...
Limitations
Main channel vs. sub-channels (FM only): The main channel is the only channel
that can receive in hybrid mode (both digital and analogue). If a frequency
has subchannels, they are broadcast i ...
