Air-fuel ratio control apparatus for internal combustion engines

摘要

A control apparatus includes an air-fuel ratio sensor for detecting an oxygen content over a wide range of operating conditions from a light load operation to a high load operation of an engine and the sensor is utilized so as to establish the desired air-fuel ratio such that the air-fuel ratio ( lambda ) becomes lambda >1, lambda =1 or lambda <1, respectively in the light, intermediate or high load operating region of the engine and the output of the air-fuel ratio sensor is utilized so as to feedback control the air-fuel ratio over the wide range of operating conditions and thereby maintain the desired air-fuel ratio in each of the operating regions.