AIR-FUEL RATIO CONTROLLER FOR MULTIPLE CYLINDER ENGINE

摘要

PURPOSE:To reduce fuel consumption while preventing misfire securely by providing a controlling means for controllably making the air-fuel ratio rich as the lean side roughness allowance limit value is reduced in reflux starting of exhaust gas. CONSTITUTION:An exhaust gas reflux controller 12 is provided to control exhaust gas reflux (EGR) to each cylinder. An exhaust gas reflux start detecting means 22 detects the time of starting EGR. In the start of EGR a controller 23 for controllably making the air-fuel ratio rich as the lean side roughness allowance limit value is reduced according to the lean side air-fuel ratio roughness allowance limit value is provided for each cylinder. Thus, the fuel consumption is reduced while misfire in the start of EGR can be securely prevented.