Emission Control Systems: Description and Operation

Engine Emission Control

NOTE: Do not permanently remove or render inoperative any part of the vehicle emission control system including related hardware. Failure to comply may violate applicable state and federal law.

NOTE: The vehicle emission vacuum routing diagrams are contained in the Description and Operation of the Evaporative Emissions system.

The gasoline engine emission control system consists of the PCV system.

PCV System

The PCV system:

- uses intake manifold vacuum to ventilate blow-by gases from the crankcase.

- returns the gases to the intake manifold for combustion.

The PCV valve:

- varies the amount of blow-by gases returned to the intake manifold based on available engine vacuum.

- is integral to the LH valve cover.