Engine cylinder deactivation to improve the performance of exhaust emission control systems

A system to regenerate an exhaust aftertreatment device of a multicylinder engine that operates primarily at an air/fuel ratio that is lean of stoichiometry, comprising:

• a controller operable to deactivate at least one cylinder using a cylinder deactivation system and operable to enrich a fuel charge to each non-deactivated cylinder using a fuel control system, based upon input from at least one sensor operable to monitor an engine operating condition and based upon input from a sensor operable to measure exhaust gas;
• wherein the exhaust aftertreatment system comprises a diesel particulate trap, an oxidation catalyst, and an NOx adsorber;
• wherein said controller is operable to maintain an operating point of the engine, and
• wherein said controller operates the engine at an air/fuel ratio that is rich of stoichiometry such that a temperature of the NOx adsorber is sufficient to desulfate the NOx adsorber.