Engine operating system for maximizing efficiency and monitoring performance of an automotive exhaust emission control system

摘要

An engine operating system includes an exhaust aftertreatment device and a fuel delivery system for providing fuel to the engine so as to cause the engine's air/fuel ratio to vary on a periodic basis. The exhaust aftertreatment device has a window of maximum operating efficiency characterized by storage and release of an exhaust constituent within the aftertreatment device. A controller operates the fuel delivery system and performs a statistical analysis of signals from an exhaust constituent concentration sensor downstream of the exhaust aftertreatment device, so as to assure that the exhaust aftertreatment device is being operated within its window of most efficient operation.