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:
Symbols in the instrument panel
The Stability Control indicator light
This light indicates different
conditions,
depending on how it illuminates.
The Stability Control indicator light
illuminates for approximately 2 seconds
...
Introduction
The Driver Alert System is designed to help a
driver who may be becoming fatigued or who
is inadvertently leaving the lane.
The Driver Alert System consists of two different
functions that can ...
Manual operation
1. Opening the sun shade: Pull the control
back to the first stop (the manual open
position) and hold it until the sun shade has
opened to the position of your choice.
2. Opening the rear edge ...
