Air fuel ratio control method

摘要

A fuel injection quantity is varied by correcting a correction value so that a mean value of a factor of air-fuel ratio feedback correction obtained from the output of an O2 sensor takes a value within a predetermined range centered at a value corresponding to a stoichiometric air-fuel ratio, and a fuel injection quantity is calculated based on a basic fuel injection quantity, the factor of air-fuel ratio feedback correction and the correction value, thereby to effect control so that the air-fuel ratio converges in proximity of the stoichiometric air-fuel ratio.