Patent ID: 8561394

Claim:
A method of heating a catalyst in an exhaust gas system of a supercharged combustion engine having direct fuel injection and a variable gas exchange valve control, the method comprising: producing a reactive exhaust gas fuel/air mixture in the exhaust gas system, wherein an air percentage of the reactive fuel/air mixture is produced by transferring air from a suction system of the combustion engine over a plurality of combustion chambers into the exhaust gas system; operating the combustion engine in an idle mode almost completely de-throttled, whereby almost completely de-throttled means an operation with at least 75% of a maximal filling that is possible under the same conditions after a cold start with a greater valve overlap and/or a greater valve overlap profile in comparison to a normal operation; determining an engine speed of the combustion engine initially after the cold start; initiating catalyst heating directly after an exceeding of a start-end engine speed; operating the combustion engine with a fuel amount to be injected before a combustion apportioned into at least two partial injections per ignition per combustion chamber, and with a suboptimal ignition angle efficiency, wherein the fuel is injected into each of the plurality of combustion chambers such that a rich fuel/air mixture develops in each of the plurality of combustion chambers; operating the combustion engine after the cold start initially with an increased idle revolution; and injecting fuel into each of the plurality of combustion chambers such that an air rate lambda of the reactive exhaust gas fuel/air mixture in the exhaust gas system is greater than or equal to 1.