JP2759913B

An air-fuel ratio feedback control method for an internal combustion engine, in which when the engine is operating in a feedback control region, the air-fuel ratio of an air-fuel mixture being supplied to the engine is controlled by the use of a correction coefficient varying in response to the output of an exhaust gas ingredient concentration sensor arranged in the exhaust system of the engine. When the engine has shifted to a predetermined high load region within the feedback control region, in which the rate of change in values of an engine operating parameter is larger than a predetermined value, the air-fuel ratio feedback control is effected by the use of a first average value of the correction coefficient, calculated when the engine is in the predetermined high load region. When the engine has shifted to a second predetermined region within the feedback control region other than the predetermined high load region, the feedback control is effected by the use of a second average value of the correction coefficient, calculated in the second predetermined region, in a manner different from that of calculating the first average value.