Patent ID: 8091348

Claim:
Method for managing an exhaust gas feedstream from an internal combustion engine selectively operative lean of stoichiometry, the method comprising: equipping the engine with an exhaust aftertreatment system comprising a three-way catalytic converter fluidly connected to a catalyzed NOx adsorber device; operating the engine; monitoring the exhaust gas feedstream; selectively directing the exhaust gas feedstream through the three-way catalytic converter and through the catalyzed NOx adsorber device based upon the monitored exhaust gas feedstream; and selectively diverting the exhaust gas feedstream around the three-way catalytic converter to the catalyzed NOx adsorber device based upon the monitored exhaust gas feedstream; wherein monitoring the exhaust gas feedstream comprises monitoring NOx emissions in the exhaust gas feedstream downstream of the catalyzed NOx adsorber device; and wherein selectively diverting the exhaust gas feedstream around the three-way catalytic converter to the catalyzed NOx adsorber device based upon the monitored exhaust gas feedstream comprises diverting the exhaust gas feedstream around the three-way catalytic converter to the catalyzed NOx adsorber device when the NOx emissions in the exhaust gas feedstream downstream of the catalyzed NOx adsorber exceeds a predetermined threshold.