Control system for internal combustion engine with enhancement of purification performance of catalytic converter

摘要

A control system for an internal combustion engine capable of improving purification performance of a catalytic converter provides an oscillation amplitude for an air/fuel ratio of an air/fuel mixture to be supplied to an internal combustion engine. The air/fuel ratio oscillation amplitude is variable depending upon an operating condition of the internal combustion engine and/or a purification performance of a catalytic converter. Corresponding to the air/fuel ratio oscillation, an oscillation amplitude of a spark ignition timing is provided. The spark ignition timing oscillation amplitude is variable depending upon the operating condition of the internal combustion engine and/or the air/fuel ratio oscillation amplitude.