Abstract: The invention relates to an exhaust gas aftertreatment system for an internal combustion engine, in particular for a gasoline engine that is spark-ignited by means of spark plugs. A four -way catalytic converter and at least one three-way catalytic converter are situated in an exhaust gas system that is connected to an outlet of the internal combustion engine. An exhaust gas burner with which hot exhaust gas is introducible into the exhaust gas system directly downstream from the four-way catalytic converter is provided at an exhaust duct of the exhaust gas system. The exhaust gas burner is supplied with fresh air by a secondary air pump. The invention further relates to a method for exhaust aftertreatment of an internal combustion engine having such an exhaust gas aftertreatment system.

Abstract: The invention relates to a method for the exhaust-gas aftertreatment of an internal combustion engine (10), and to an internal combustion engine (10) having an exhaust-gas aftertreatment device for carrying out a method of said type. The internal combustion engine (10) is supplied with fresh air by way of a compressor (18), has an adjustable valve control means (12) for the inlet valves (14) and/or the outlet valves (16), and is connected to an exhaust duct (20), wherein, in the exhaust duct (20), there is arranged a first three-way catalytic converter (24), and an injection valve (26) for introducing fuel into the exhaust duct (20) is arranged, as viewed in the flow direction of an exhaust gas of the internal combustion engine (10), downstream of an outlet (22) of the internal combustion engine (10) and upstream of the first three-way catalytic converter (24).

Abstract: A method for heating an electrically heatable catalytic converter in an exhaust duct of a motor vehicle having a combustion engine. To heat the catalytic converter prior to a start of the combustion engine, the catalytic converter should already be electrically heated prior to the start of the combustion engine, and the oxygen storage capacity of the electrically heatable catalytic converter should be filled. Thus, an efficient exhaust-gas aftertreatment is made possible already at the start of the combustion engine. A further heating of the catalytic converter by a combined electrical and chemical heating takes place following an electrical preheating phase after the start of the combustion engine by the exothermic reaction of unburned fuel components on a catalytically active surface of the electrically heatable catalytic converter. Also, a motor vehicle having a combustion engine and an exhaust system in which a method according to the present invention is implemented.

Abstract: The invention relative to an exhaust gas system (10) for a spark-ignition internal combustion engine (12), comprising an HC adsorber (22) as well as, downstream from it, a catalytic converter (20) designed at least to convert hydrocarbons (HC), and it also relates to a method for operating an exhaust gas system (10). It is provided that a burner device (30) which is operated or can be operated with air and fuel is installed downstream from the HC adsorber (22) and upstream from the catalytic converter (20).