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:
Removing the headlight housing
1. Switch off the ignition by briefly pressing
the START/STOP ENGINE button.
2. Remove the remote key from the ignition
slot1.
3. (Upper illustration under "Headlight housing").
&nb ...
Symbols and messages in the display
...
Maintenance
Use a screw driver to open the caps or cover and a flashlight to inspect
the level.
If necessary, add distilled water. The level should never be above the indicator.
The fluid level should b ...
