Abstract: A multi-cylinder air-compressing injection-type internal-combustion engine having a nitric oxide adsorber catalyst and an exhaust gas return device. In order to increase the hydrocarbon fraction in the exhaust gas in front of an exhaust gas aftertreatment device during a regeneration phase and to reduce the oxygen content, exhaust gas pipes of the cylinders are divided into at least two flows, which extend separately from one another at least along a distance. An increased hydrocarbon emission is generated exclusively in the cylinders of one of the flows at times. Another of the flows is connected by way of the exhaust gas return device with an air intake pipe of the internal-combustion engine.

Abstract: A system and a process for operating a diesel engine using an automatic engine control which, as a function of characteristic diagrams, automatically controls the operation of the diesel engine and permits an automatic rich/lean controlling of the diesel engine. The automatic engine control includes a computer which, as a function of predetermined change-over criteria, causes a change-over to the rich or the lean operation of the diesel engine. A sensor system communicates with the computer and monitors the parameters necessary for change-over criteria. A memory communicates with the computer, the memory storing separate characteristic diagrams for the operation of the diesel engine for the lean operation and for the rich operation.