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.
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Environment
Volvo and the environment
Volvo is committed to the well being of its customers.
As a natural part of this commitment,
we care about the environment in which we all
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Oil specifications
Engine oil must meet the minimum ILSAC
specification GF-4, API SL, or ACEA A1/B1.
Lower quality oils may not offer the same fuel
economy, engine performance, or engine protection.
Depending on ...
The Federal Clean Air Act – U.S.
The Federal Clean Air Act requires vehicle
manufacturers to furnish written instructions to
the ultimate purchaser to assure the proper
servicing and function of the components that
control em ...
