To reduce emissions of harmful substances from exhaust gases (CO, HC, NOx) the engine control system has been modified with the addition of special elements. The changes affected the combustion chamber, intake manifold, camshaft and ignition system, which form the main control system.
Additional control devices include an exhaust gas recirculation (EGR) system and a catalytic converter.
These systems have been combined into an effective system that manages emissions reduction while maintaining good overall vehicle drivability and fuel economy.