CONTROLLER FOR INTERNAL COMBUSTION ENGINE

A controller for an internal combustion engine is configured to execute a rich air-fuel ratio control for performing fuel injection while setting a target equivalence ratio such that, at recovery from a fuel cutoff process, an air-fuel ratio of air-fuel mixture is richer than a stoichiometric air-fuel ratio. The controller is configured to execute a target equivalence ratio setting process for setting the target equivalence ratio that is maintained during execution of the rich air-fuel ratio control such that the target equivalence ratio increases as an air excess ratio that is calculated from an output value of a second air-fuel ratio sensor at start of the rich air-fuel ratio control increases.