An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.

A motor vehicle emission control system includes a three zone catalytic converter component having a honeycomb support body with catalytically active coating having a precious metal content applied on the channel walls. The first coating zone extends in the longitudinal direction from the inlet-side end to a first coating boundary and has a first precious metal content. The second coating zone extends in the longitudinal direction from the first coating boundary to a second coating boundary situated downstream from the first coating boundary and has a second precious metal content that is lower than the first precious metal content. The third coating zone extends from the second coating boundary to the outlet-side end and has a third precious metal content that is lower than the second precious metal content. The coating has oxidation catalyst activity and is free of rhodium.

An internal combustion engine fluidly coupled to an exhaust aftertreatment system includes a particulate filter device, a first selective catalytic reduction device disposed upstream relative to a second selective catalytic reduction device, and an injection system disposed to inject a reductant into the exhaust gas feedstream upstream relative to the first selective catalytic reduction device. A method for controlling the internal combustion engine includes monitoring engine operation, and determining an amount of particulate matter stored on the particulate filter based thereon. An amount of reductant stored on the second selective catalytic reduction device and operating conditions associated with the exhaust aftertreatment system are also determined. A process to regenerate the particulate filter is executed only when the amount of reductant stored on the second selective catalytic reduction device is greater than a minimum threshold and the operating conditions are conducive to regenerating of the particulate filter.

An aftertreatment system comprises a SCR system including a catalyst formulated to decompose constituents of an exhaust gas passing therethrough. A filter is positioned upstream of the SCR system. The filter comprises a sulfur suppressing compound formulated to reduce an amount of SOx gases included in the exhaust gas flowing through the aftertreatment system. In particular embodiments, the filter comprises a filter housing and a filter element positioned within the filter housing. The filter element comprises the sulfur suppressing compound.

A high-end processing device for purification of exhaust of a diesel engine includes a connection channel, a plurality of catalytic converters, a plurality of direct-passage ceramic filters, and at least one wall-flow filter. The catalytic converters are arranged, in a manner of being spaced from each other, at a front portion of an exhaust gas flow path defined by the connection channel. The direct-passage ceramic filters and the wall-flow filter are arranged, in a manner of being spaced from each other, at a rear portion of the exhaust gas flow path of the connection channel. The direct-passage ceramic filters and the wall-flow filter are impregnated with urea or ammonia and dried so as to reduce nitrogen oxides (NOx) into nitrogen and water to reduce impact to the environment.

An exhaust aftertreatment unit for cleaning exhaust gases. The exhaust aftertreatment unit includes an emission reducing module being a diesel particulate filter, DPF, and/or a diesel oxidation catalyst, DOC, a selective catalyst reduction, SCR, catalyst, an electrical heating element arranged upstream of the SCR catalyst, a casing housing at least the emission reducing module, and a service lid removably arranged to cover a service opening of the casing through which the emission reducing module may be accessed. The electrical heating element is removably arranged relative the casing and is arranged accessible upon removal of the service lid.

Exhaust systems and passenger service vehicles, for example, buses are used together. The exhaust system can be arranged, in use, to be above an engine compartment. The exhaust system includes a first filter and a second filter, each filter having an inlet and an outlet. The inlets are inline with the respective first and second filters, and the outlets are transversely arranged with reference to the respective filters. Vehicles may have an overall length of about 35 feet or less and have an unladen weight of around 25,000 lbs or less.

A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s4103); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

A control device for an internal combustion engine includes: an upstream catalyst; a downstream catalyst that is provided further downstream than the upstream catalyst in the exhaust flow direction; a downstream air-fuel ratio detection device that is provided between these catalysts; a storage amount estimation device that estimates the oxygen storage amount of the downstream catalyst; and an inflow air-fuel ratio control device that controls the air-fuel ratio of the exhaust gas flowing into the upstream catalyst such that the air-fuel ratio of the exhaust gas reaches a target air-fuel ratio.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first treatment element positioned within the exhaust gas pathway, a first injector configured to introduce a first reductant into the exhaust gas pathway upstream of the first treatment element, a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element, a second treatment element positioned within the exhaust gas pathway downstream of the second injector, the second treatment element including a SCR element, and a controller configured to periodically initiate a desulfuring regeneration cycle by increasing a concentration of hydrocarbons in the exhaust gas and increasing the flow of the first reductant through the first injector to oxidize sulfur contamination in the first treatment element at temperatures between 400 and 500 degrees Celsius.