Air-fuel ratio control method and its apparatus

摘要

An apparatus for controlling an air-fuel ratio of a combustion engine with a memory device for storing correct values for air-fuel control in accordance with an intake condition of said combustion engine and a rotation speed of the same. In the apparatus, an air-fuel ratio represented by the exhaust gas composition of the internal combustion engine is sensed and the sensed value is integrated. When the integrated value from the integrator fails within a predetermined range of values, one of the correction values for the air-fuel ratio control is corrected in accordance with a current condition of the internal combustion engine. When the integrated value falls outside the predetermined range, the correction values are replaced by a predetermined reference value and an air-fuel ratio of mixture supplied to the combustion engine is controlled in accordance with the correction values for the air-fuel ratio stored.