Patent attributes
A system operable to control an exhaust gas emission of an engine, includes a catalytic converter; a fuel cutter, a change executor, a correlation value provider, an adjuster, and a controller. The change executor is operable to execute changing of an air-fuel ratio of the engine to a rich air-fuel ratio after the fuel supply is once stopped by the fuel cutter and then resumed. The correlation value provider is operable to provide a correlation value correlated to a change amount of the air-fuel ratio caused by the change executor based on a driving condition of the engine. The adjuster is operable to adjust the correlation value based on a parameter indicative of a capability of the catalytic converter. The controller is operable to cause the change executor to execute the changing based on the adjusted correlation value.
