Controller and control method for internal combustion engine

A method for controlling an internal combustion engine, the internal combustion engine including

• an in-cylinder injection valve that injects fuel into a cylinder,
• a port injection valve that injects fuel into an intake port,
• an ignition device that ignites, by a spark, an air-fuel mixture of fuel and air introduced into the cylinder,
• an exhaust passage through which gas discharged out of the cylinder flows, and
• a three-way catalyst device provided in the exhaust passage,
• the method comprising:
• executing a fuel introduction process of introducing the air-fuel mixture, which has been introduced into the cylinder, into the exhaust passage without burning the air-fuel mixture in the cylinder,
• wherein the fuel introduction process is executed in a state in which only the port injection valve of the in-cylinder injection valve and the port injection valve performs fuel injection.

A controller configured to control an internal combustion engine, the internal combustion engine including

• an in-cylinder injection valve that injects fuel into a cylinder,
• a port injection valve that injects fuel into an intake port,
• an ignition device that ignites, by a spark, an air-fuel mixture of fuel and air introduced into the cylinder,
• an exhaust passage through which gas discharged out of the cylinder flows, and
• a three-way catalyst device provided in the exhaust passage,
• the controller comprising:
• processing circuitry configured to execute a fuel introduction process of introducing the air-fuel mixture, which has been introduced into the cylinder, into the exhaust passage without burning the air-fuel mixture in the cylinder,
• wherein the processing circuitry is configured to execute the fuel introduction process in a state in which only the port injection valve of the in-cylinder injection valve and the port injection valve performs fuel injection.