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:
Children should be seated safely
Volvo recommends the proper use of restraint
systems for all occupants including children.
Remember that, regardless of age and size, a
child should always be properly restrained in a
vehicle.
...
Convertible Positives
It takes about 30 seconds to raise or lower the power-retractable hardtop. It
motors up and down smoothly and quietly, which isn't common, even among luxury
models. And in what was the most welcom ...
Engine specifications
A This engine may not be available on all markets ...
