The Fuel and air metering and auxiliary emission control is related two systems:
In automobiles, the emission control system is employed to limit the discharge of harmful gases from the internal-combustion engine and other components. Three primary sources of these gases are the engine exhaust, the crankcase, and the fuel tank and carburetor.
An auxiliary Emission Control Strategy (AECS) means any system, function, device, or element. Design, installed toon an engine or on a vehicle, that senses or responds to operating variables, such as vehicle speed, engine rpm, transmission gear, temperature, intake pressure, or any other.