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 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.