Abstract: A method is described for identifying fuel composition from an index ratio of oxygen sensors upstream and downstream of a catalyst of the engine. Different index ratios are achieved for different fuel compositions, and thus it is possible to identify fuel composition, such as fuel alcohol content, based on changes in the index ratio.

Abstract: A system for an engine is shown that includes an upstream emission control device and a downstream emission control device. The upstream device has a washcoat having a predetermined amount of precious metal disassociated with NOx storage material. In one example, the upstream emission control device located in a close-coupled location receiving untreated exhaust gasses from the engine. A controller is utilized for adjusting parameters of the engine. For example, the controller operates the engine lean, with periodic rich operation to purge stored NOx during at least a portion of low engine airflow and low exhaust temperature conditions. The controller also operates the engine near stoichiometry during at least a portion of other conditions.

Abstract: A method is described for operating an engine and an emission control system downstream of the engine, the emission control system including a catalyst, an exhaust gas path coupling the engine to the catalyst, a first air-fuel ratio sensor positioned upstream of the catalyst and a second air-fuel ratio sensor positioned adjacent to or downstream of the catalyst. The method includes correlating variation in the catalyst performance across air-fuel ratios, as identified via the first and second sensors, to fuel composition of fuel combusted in the engine.

Abstract: A fugitive hydrocarbon treatment module and system for controlling the emission of hydrocarbons from the air intake system of an engine includes a zeolite adsorber unit positioned in the air intake system such that all gases flowing to and from the engine through the air intake system pass through the adsorber, so as to allow hydrocarbons borne by the gases to be adsorbed upon the substrate of the adsorber unit when the engine is shut down and desorbed from the adsorber unit when the engine is in operation.

Abstract: A method is described for operating an engine coupled to an upstream and downstream emission control device that stores and reacts oxidants such as NOx. The method transitions from lean to stoichiometric or rich operation under various conditions. The amount of fuel used during the stoichiometric or rich operation is minimized by using an upstream three-way catalyst primarily used for NOx storage, and a downstream three-way catalyst primarily used for oxygen storage.

Abstract: A system for an engine has an upstream emission control device with a washcoat having a predetermined amount of precious metal disassociated with NOx storage material, where the upstream emission control device in a close coupled location to an exhaust manifold of the engine. The system also includes a downstream emission control device coupled to the upstream emission control device. Further, a controller is used for operating the engine lean with retarded ignition timing to generate heat and raise temperatures of said upstream and downstream emission control devices. The controller also determines whether temperature of said upstream device has reached a predetermined value, and in response to said determination, operates the engine rich at least to reduce NOx stored in said upstream emission control device during said lean operation.

Abstract: A method and system are provided for monitoring exhaust gas conversion efficiency of a catalytic converter during operation of an internal combustion engine coupled to the catalytic converter. The system includes an upstream exhaust gas sensor interposed the engine and the catalytic converter for generating a first signal based on the exhaust gas upstream of the converter. A downstream exhaust gas sensor is interposed the catalytic converter and atmosphere for generating a second signal based on the exhaust gas downstream of the converter. A phase shift detector is provided for estimating a phase shift between the first and second signals. A processor is provided for aligning the first and second signals such that the resulting phase shift between the first and second signals is substantially an integer multiple of &pgr; radians and for determining conversion efficiency of the catalytic converter based such phase aligned first and second signals.