Emission Control Systems: Description and Operation

Engine and Emission Control System Description

The engine and emission control system is divided into 4 major sub-systems: air intake system, fuel delivery system, electronic control system and emission control system.
The air intake system includes air cleaner, mass air flow sensor, throttle body, IMT (Intake Manifold turning) valve and intake manifold.
The fuel delivery system includes fuel pump, delivery pipe, fuel pressure regulator, fuel injectors, etc.
The electronic control system includes ECM, various sensors and controlled devices.
The emission control system includes EVAP and PCV systems.
When hoses are disconnected and system components are removed for service, be sure to reinstall components properly and route and connect hoses correctly after service. Refer to the figure below for proper routing of hoses.