Abstract: A method of controlling an internal combustion engine is provided, in which at least two operating states are differentiated, at least one operating variable of the engine being controlled, a setpoint torque being predetermined on the basis of the optimum operating point for the respective operating state and on the basis of the position of a throttle valve operated by the driver, and the value of at least one operating variable to be output being determined from the setpoint torque. A cylinder-individual firing angle retardation value is predetermined by a knock control system, so that the cylinder-individual firing angle retardation value is taken into account directly in calculating the setpoint torque.

Abstract: A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, such as after an engine cold start, the method operates an engine with a first group of cylinders having a first ignition timing, and a second group of cylinders having a second ignition timing more retarded than the first group. In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also can change to combusting all cylinders at substantially the same ignition timing under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.