METHOD AND APPARATUS FOR REGENERATING AN AFTERTREATMENT DEVICE FOR A SPARK-IGNITION DIRECT-INJECTION ENGINE

摘要

The disclosure sets forth operating a spark-ignition, direct-fuel injection internal combustion engine equipped with an exhaust aftertreatment system including a lean-NOx adsorber device. The engine is operated substantially un-throttled and at a lean air/fuel ratio and a first fuel pulse is injected to meet an engine output torque during a compression stroke of each engine cycle prior to a spark- ignition event. When regeneration of the lean-NOx adsorber device is commanded, a second fuel pulse is injected during a second engine stroke of each engine cycle.