Engine Emission Control

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.

The engine emission control system consists of the:

- EGR system.
- PCV system.



EGR System

The EGR system:

- returns a small amount of exhaust gas into the engine for recombustion.
- reduces the overall combustion temperature and provides a significant reduction of Nitrogen Oxides (NOX).

The EGR valve:

- is electronically controlled by the PCM.
- is connected to the exhaust manifold by the EGR valve to exhaust manifold tube.
- controls recirculated exhaust gas flow to the intake manifold.
- monitors the flow of recirculated exhaust gases through the EGR valve to exhaust manifold tube.
- returns a signal to the PCM.

The amount of recirculated exhaust gas depends upon:

- engine rpm.
- intake manifold vacuum.
- exhaust back pressure.
- engine coolant temperature.
- throttle position.



PCV System

The PCV system:

- uses intake manifold vacuum to ventilate blow-by vapors from the crankcase.
- returns the vapors to the intake manifold for combustion.

The PCV valve:

- varies the amount of blow-by vapors returned to the intake manifold based on available engine vacuum.
- is heated electronically.



Vehicle Emission Vacuum Routing