Emission Control Systems: Description and Operation

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.