ENGINE AIR-FUEL RATIO CONTROL DEVICE

An engine air-fuel ratio control device is configured to be used in a vehicle including a power transmission device configured to transmit power between an output shaft of an engine and an input shaft of a transmission and to execute a lean-burn control that puts an air-fuel ratio of the engine into a lean state. An engine controller executes a fuel injection feedback control such that the air-fuel ratio becomes a lean target value after the power transmission device is released during a deceleration of the vehicle. An engine stall predictor predicts a stall of the engine on a basis of a deceleration indicator that is correlated with a deceleration degree of the vehicle in a state in which the power transmission device is released. A lean-burn control canceler cancels the lean-burn control in a case in which the engine is predicted to stall.