TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The gaseous hydrocarbon comprises methane. The fuel is a gaseous fuel.    TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Component: The reformer is off-line and is disposed upstream of the NOx adsorber and downstream of the oxidizer. The reformer and the oxidizer are combined into a partial oxidation catalyst (POX). The oxidizer comprises a methane oxidation catalyst, where the first gas line is connected to direct the second quantity of methane to the oxidation catalyst (42). The system further comprises a second gas line connected to deliver the second quantity of methane to the oxidation catalyst comprising a metal substrate; a heat exchanger for transferring heat from the exhaust gases to the reformer; a heater for heating the reformer(s) and the first quantity of exhaust gases upstream of the oxidizer, and for heating second oxidizer(s) and a quantity of air; an air line capable of directing the heated air to the reformer; and a by-pass line (12) for directing the second quantity of exhaust gas around the NOx adsorber. The heated second oxidizer is capable of oxidizing methane in the air. The first gas line directs the methane to the second oxidizer. The second gas line directs the second quantity of methane from the hydrocarbon store (36) to the air line downstream of the oxidizer and upstream of the reformer.Preferred Method: The reforming step is carried out in an exhaust gas environment. A second quantity of methane is oxidized to reduce the oxygen concentration of the exhaust gases. The hydrogen is oxidized to reduce the oxygen concentration of the exhaust gases. The first quantity of methane is taken from a residual portion of the second quantity of methane not oxidized. The creating step occurs within the exhaust line. The method further comprises reforming the first quantity of methane off-line; heating the first quantity of methane prior to the step of reforming the first quantity of methane; and heating the second quantity of methane by oxidation of hydrogen where oxidation of the second quantity of methane is initiated. The heating step is performed by permitting heat exchange with the exhaust gases. A second quantity of exhaust gas is by-passed around the NOx adsorber during a regeneration cycle. An emission gas recirculation is utilized during the regeneration cycle. The oxidizer is warmed prior to commencement of the regeneration cycle by directing a third quantity of methane into the oxidizer. The gaseous fuel is directly injected into the combustion chamber.