Patent ID: 8297258

Claim:
A method for operating an internal combustion engine having multiple cylinders, fuel being injectable into the multiple cylinders via corresponding injectors, corresponding intake valves allowing entry of air in order to form an air-fuel mixture in the cylinders for providing a drive torque, and combustion exhaust gas being dischargeable from the cylinders via a catalytic converter, the method comprising: operating the internal combustion engine in a first engine operating mode in which no fuel is injected into at least one first cylinder, so that the at least one first cylinder does not contribute to the drive torque, and fuel is only injected into at least one second cylinder in order to provide a drive torque; switching to a second engine operating mode in which fuel is injected into the at least one first cylinder and into the at least one second cylinder, so that the at least one first cylinder and the at least one second cylinder contribute to providing the drive torque; and determining a quantity of fuel which has penetrated into the at least one first cylinder as a result of leakage from corresponding injectors into combustion chambers of the at least one first cylinder during a first engine operating mode, the quantity being determined as a function of at least one of a rotational speed and a pressure in the fuel delivery system for at least one injector; wherein in switching to the second engine operating mode the combustion is carried out using excess air in the at least one second cylinder, so that a portion of the air let into the at least one second cylinder, together with the combustion exhaust gas, passes into the catalytic converter.