Operation CHARM: Car repair manuals for everyone.

Emission Control Systems: Description and Operation

ENGINE EMISSION CONTROL







The engine emission control system consists of the:
- exhaust gas recirculation (EGR) valve
- differential pressure feedback EGR
- EGR vacuum regulator solenoid
- EGR valve tube
- positive crankcase ventilation (PCV) system

The engine emissions control system:
- cycles crankcase gases back through the engine intake system.
- regulates ventilating air and blow-by fuel vapors.
- reintroduces exhaust gases into the combustion cycle.
- assists in the reduction of nitrogen oxides.

The PCV system uses intake manifold vacuum to ventilate the crankcase and return the fumes to the intake manifold for combustion. If equipped, a crankcase vent oil separator is used to prevent oil from entering the PCV system.