Abstract: Methods and systems are provided for expediting emission control device heating. In one example, a method may include flowing air from an intake of an engine to one or more emission control devices via an air injection system while operating a turbocharger via an electric motor to maintain a desired airflow to the engine in response to an emission control device heating condition. In this way, fresh air is provided to the one or more emission control devices without degrading engine performance or increasing engine speed.

Abstract: Methods and systems are provided for expediting emission control device heating. In one example, a method may include flowing air from an intake of an engine to one or more emission control devices via an air injection system while operating a turbocharger via an electric motor to maintain a desired airflow to the engine in response to an emission control device heating condition. In this way, fresh air is provided to the one or more emission control devices without degrading engine performance or increasing engine speed.

Abstract: A process for controlling an exhaust system can comprise flowing exhaust gas from the engine past a first oxygen sensor, through a NOx adsorber, past a second oxygen sensor, through a catalyst and past a third oxygen sensor, wherein the first oxygen sensor, the second oxygen sensor, and the third oxygen sensor, are in operable communication with an electronic control module, and using a switching delay between the first oxygen sensor and the second oxygen sensor to determine a NOx value, wherein the NOx value is selected from the group consisting of a NOx regeneration time, a stored NOx amount, a NOx storage efficiency, and combinations comprising at least one of the foregoing NOx values. A desulfurization process can be initiated when the NOx value is less than or equal to a first selected value. During the desulfurization process, when the third oxygen sensor signals a condition rich of stoichiometry, oxygen can be provided to the catalyst.

Abstract: A diagnostic system for monitoring catalyst performance in an exhaust system comprises a plurality of treatment devices catalytically treating an exhaust gas stream, and a plurality of gas sensors for monitoring the catalyst performance of the treatment devices to determine when sulfur poisoning occurs. An on-board diagnostic system receives signals from the gas sensors, and, based upon response time differentials between sensors, determines whether the treatment devices are experiencing sulfur poisoning.

Abstract: Described herein is a NOx adsorber that reduces the amount of NOx in the exhaust stream of a lean-burn internal combustion engine. The adsorber incorporates a small amount of lithium along with a catalyst, an alkali material, and a support material. The lithium acts to facilitate the reduction of absorbed NOx, thereby lowering NOx concentrations in the exhaust gas.

Abstract: An exhaust gas catalyst system, comprises: a sulfur trap warm-up catalyst, housed within the exhaust stream and comprising: a sulfur scavenger component; and a NOX adsorber catalyst, housed within the exhaust stream downstream from said sulfur trap in an underfloor position. The method of reducing sulfur poisoning of a nitrogen oxide adsorber, housed within an exhaust gas catalyst system, comprises: placing a sulfur trap within the exhaust stream upstream from a NOX adsorber, wherein said sulfur trap comprises: a sulfur scavenger component.