Abstract: An aftertreatment system for an engine emissions trap or adsorber having a mechanism for increasing exhaust temperature of an engine to regenerate the trap or adsorber. The mechanism may include a cylinder cutout. The cylinder cutout may be actuated various ways including a use of cylinder valve control. Cutout of a cylinder or cylinders may be rotated among the cylinders of the engine. There may be sensors on the engine and in its exhaust system connected to a processor. The processor may provide an output indicating a degree of need for regenerating the trap or adsorber. An output of the processor also may be connected to the mechanism for increasing exhaust temperature so as to effect regeneration as needed. The emissions of concern may be NOx. The engine for example may be a diesel.