EMISSION CONTROL SYSTEM GENERAL GENERAL

  1. OUTLINE

    1. Three-Way Catalytic converter (TWC) is used in exhaust system.

    2. Exhaust Gas Recirculation (EGR) control, which reduces the combustion temperature by recirculation of the exhaust gas and also reduces NOx emissions and improves fuel economy, is used.

    3. The ECM performs air fuel ratio feedback control based on signals from the heated oxygen sensor, and controls the fuel injection amount so that the air fuel ratio comes close to the stoichiometric air fuel ratio at which the highest purifying efficiency of CO, HC and NOx is obtained.

    4. A blowby gas ventilation system, which efficiently ventilates blowby gas containing HC from the crankcase, is used.

    5. Evaporative emission control, which regulates the purge flow of evaporative emissions (HC) in the canister in accordance with the engine operating conditions, is used.

    6. Heated oxygen sensor heater control, which maintains the temperature of the heated oxygen sensors at an appropriate level, is used, to improve the detection accuracy of oxygen concentration in the exhaust gas.