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:
Reporting safety defects in the U.S.
If you believe that your vehicle has a
defect which could cause a crash or
could cause injury or death, you
should immediately inform the
National Highway Traffic Safety
Administration (NHTS ...
RSE-AUX connectors and 12-voltsocket
The three color-coded (yellow-white-red) RSEAUX
connectors can be used to connect an
auxiliary device to the RSE system. Always follow
the connection instructions provided with
the auxiliary devic ...
Cold weather precautions
If you wish to check your vehicle before the approach of cold weather, the following
advice is worth noting:
Make sure that the engine coolant contains 50 percent antifreeze. Any other
mixtur ...
