Emission Control Systems: Description and Operation

Engine and Emission Control System Description

The engine and emission control system has 4 major sub-systems: air intake system, fuel delivery system, electronic control system and emission control system. Air intake system includes air cleaner, mass air flow sensor, throttle body, idle air control valve and intake manifold.

Fuel delivery system includes fuel pump, delivery pipe, fuel pressure regulator, fuel injectors, etc. Electronic control system includes ECM, various sensors and controlled devices. Emission control system includes EGR, EVAP and PCV systems.

When hoses are disconnected and system components are removed for service, reinstall components properly, and route and connect hoses correctly after service. Refer to Engine and Emission Control System Hose and Piping Location for proper routing of hoses.