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:
Generator warning light
If the light comes on while the
engine is running, have the charging
system checked. ...
Style
There are three C70 T5 trim levels: base, Premier Plus and Platinum. Our test
car was a Platinum with the Inscription option package. The Platinum trim
includes a number of exterior and interior a ...
Introduction
Information display and controls
1 READ–press to acknowledge/confirm/erase a message)
2 Thumb wheel (used to scroll among the trip computer menus)
3 RESET–resets certain functions
To scroll thro ...
