Attenuation of engine harshness during lean-to rich transitions

摘要

Engine systems and methods for accomplishing regeneration of a NOx adsorber ( 28 ) using in-cylinder post-injection in a way that creates a lean-rich transition (FIG. 3 ) for regenerating the NOx adsorber while attenuating engine torque output fluctuations during the transition without the necessity of using torque sensing to attenuate the fluctuations.