Abstract: The invention relates to a method for operating a diesel engine in which an air ratio (?) of the fuel which is to be burnt and of the combustion air supplied is set by a control unit (14) according to predetermined values. When a value (15) which is predetermined as a switching criterion is recorded, the control unit (14) switches to a special operating mode for regeneration of a catalytic converter (22) and sets the fuel/air ratio according to predetermined values for this operating mode. To achieve more effective regeneration of the catalytic converter, according to the invention it is provided that at least one afterinjection, which is separated in time from a main injection, of fuel which is also to be burnt takes place in the special operating mode.

Abstract: In a method for operating a diesel engine and a diesel engine, wherein engine emission control is provided by switching between a lean mode with superstoichiometric combustion air ratio ?>1 and a rich mode with substoichiometric combustion air ratio ?<1, the engine-torque fluctuations during the switching are determined and engine parameters which influence the engine torque, are adjusted so as to keep the engine torque constant during the switchover.

Abstract: In a method for operating an internal combustion engine using exhaust gas purification system, and internal combustion engine, the method for operating an internal combustion engine with exhaust gas purification system, in which a rich mode of the internal combustion engine with a rich exhaust gas composition and a lean mode of the internal combustion engine with a lean exhaust gas composition are set alternately, and by the exhaust gas purification system with a rich exhaust gas composition ammonia is synthesized and stored and with a lean exhaust gas composition nitrogen oxides are reduced to form nitrogen by means of the stored ammonia.

Abstract: The invention relates to a method for operating a diesel engine in which an air ratio (&lgr;) of the fuel which is to be burnt and of the combustion air supplied is set by a control unit (14) according to predetermined values. When a value (15) which is predetermined as a switching criterion is recorded, the control unit (14) switches to a special operating mode for regeneration of a catalytic converter (22) and sets the fuel/air ratio according to predetermined values for this operating mode.

Abstract: In a method for operating a combustion engine having an exhaust-gas turbocharger, it is possible to switch over between a normal operation and a special operation. In the special operation, at least one main fuel injection and at least one secondary fuel injection are provided. In response to a positive load jump, a switch-over between the normal operation and the special operation provided for increasing the exhaust gas enthalpy is performed, the secondary fuel injection in the special operation being adjusted so that it substantially burns in the combustion chamber and causes an increase in the exhaust gas enthalpy as well as an adjustment of a rich or a lean exhaust gas composition. The method according to the present invention may be used, for example, in a motor vehicle having a diesel engine.

Abstract: In a method for operating a diesel engine and a diesel engine, wherein engine emission control is provided by switching between a lean mode with superstoichiometric combustion air ratio &lgr;>1 and a rich mode with substoichiometric combustion air ratio &lgr;<1, the engine-torque fluctuations during the switching are determined and engine parameters which influence the engine torque, are adjusted so as to keep the engine torque constant during the switchover.

Abstract: In a method for operating an internal combustion engine using exhaust gas purification system, and internal combustion engine, the method for operating an internal combustion engine with exhaust gas purification system, in which a rich mode of the internal combustion engine with a rich exhaust gas composition and a lean mode of the internal combustion engine with a lean exhaust gas composition are set alternately, and by the exhaust gas purification system with a rich exhaust gas composition ammonia is synthesized and stored and with a lean exhaust gas composition nitrogen oxides are reduced to form nitrogen by means of the stored ammonia.

Abstract: In a method for operating a combustion engine having an exhaust-gas turbocharger, it is possible to switch over between a normal operation and a special operation. In the special operation, at least one main fuel injection and at least one secondary fuel injection are provided. In response to a positive load jump, a switch-over between the normal operation and the special operation provided for increasing the exhaust gas enthalpy is performed, the secondary fuel injection in the special operation being adjusted so that it substantially burns in the combustion chamber and causes an increase in the exhaust gas enthalpy as well as an adjustment of a rich or a lean exhaust gas composition. The method according to the present invention may be used, for example, in a motor vehicle having a diesel engine.