A lean-burn internal combustion engine and an exhaust aftertreatment system having an oxidation catalyst are described. A controller determines a fueling rate and a mass flowrate of the exhaust gas feedstream. An inlet temperature of the exhaust gas feedstream upstream of the oxidation catalyst is determined via the first temperature sensor, and an in-use outlet temperature of the exhaust gas feedstream is determined downstream of the oxidation catalyst via the second temperature sensor. An expected outlet temperature from the oxidation catalyst is determined based upon the inlet temperature, the fueling rate, and the mass flowrate of the exhaust gas feedstream. The oxidation catalyst is evaluated based upon the expected outlet temperature and the in-use outlet temperature.

The present disclosure is directed towards a filter arrangement for a reductant supply system of a selective catalytic reduction system. The reductant supply system comprises a tank and a suction tube mounted at least partially in the tank for receiving reductant liquid from the tank. The filter arrangement comprises a restraining body, a filter at least partially forming a filter chamber, a filter outlet from the filter chamber formed through the restraining body and/or filter and a filter mount mounted to the restraining body and/or filter. The restraining body extends radially outwardly from the filter mount and is configured to restrain the filter such that, under the effect of buoyancy in the tank in use, gas in the filter chamber is directed towards the filter outlet.

One or more techniques and/or systems are disclosed for providing localized heating within an engine exhaust aftertreatment system. The localized heating includes DEF injector nozzle heating with a DEF dispensing system having a DEF fluid supply and a DEF injector fluidly coupled to the DEF fluid supply. The DEF injector includes a DEF injector nozzle. The DEF dispensing system further includes a DEF heater positioned in proximity to the DEF injector nozzle. The DEF heater is configured to locally heat an area surrounding the DEF injector nozzle.

One or more techniques and/or systems are disclosed for providing localized heating within an engine exhaust aftertreatment system. The localized heating includes DEF injector nozzle heating with a DEF dispensing system having a DEF fluid supply and a DEF injector fluidly coupled to the DEF fluid supply. The DEF injector includes a DEF injector nozzle. The DEF dispensing system further includes a DEF heater positioned in proximity to the DEF injector nozzle. The DEF heater is configured to locally heat an area surrounding the DEF injector nozzle.

A method is disclosed for cleaning a component of an exhaust aftertreatment system located downstream of a combustion engine in an exhaust flow path delimited by an outer wall. The exhaust aftertreatment system includes a first device releasably mounted in the outer wall upstream of the component and a second device releasably mounted in the outer wall downstream of the component, each of the devices being a sensor or an injector. The method includes sealing the exhaust flow path upstream of the first device and downstream of the second device, removing at least the first and second devices, thereby providing at least two openings in the outer wall, so that a cleaning flow path is provided, and introducing cleaning fluid into at least one of the openings, so that the cleaning fluid flows across the component via the cleaning flow path.

An exhaust gas purification system for an internal combustion engine is provided with a filter including a selective catalytic reduction NOx catalyst carried thereon. Further, a post-catalyst is provided for an exhaust gas passage disposed on a downstream side from the filter. The post-catalyst has an oxidizing function, and the post-catalyst has such a function that the production of N.sub.2 based on the oxidation of ammonia is facilitated in a predetermined first temperature area. A filter regeneration process execution unit is programmed to control the temperature of the post-catalyst to be in the first temperature area while adjusting the temperature of the filter to be in a predetermined second temperature area lower than a filter regeneration temperature during a certain period of time.

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.

A method is provided for determining exhaust mass flow through a diesel particulate filter (DPF) in an engine arrangement including an engine and an exhaust after treatment system (EATS) comprising the DPF. The method comprises determining soot loading and soot distribution in the DPF, measuring pressure drop over the DPF, measuring pressure in the DPF, measuring temperature in the DPF, and determining exhaust mass flow through the DPF as a function of the measured pressure drop, the measured pressure, the measured temperature, and the soot loading and soot distribution. An arrangement is also provided for determining exhaust mass flow through a diesel particulate filter. A method for controlling one or more engine components, and an engine, are also provided.

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.

An under-floor catalyst (33) includes a GPF (41) capable of trapping fine exhaust particles in exhaust gas, and a downstream-side catalyst (42) positioned on the downstream side of GPF (41). GPF (41) can be supplied with secondary air. When an internal combustion engine (10) is stopped during travel, the secondary air is supplied to GPF (41) in which the fine exhaust particles are accumulated. At this time, the temperature of GPF (41) is equal to or higher than a predetermined temperature. Thus, a deterioration in the exhaust gas purification performance of under-floor catalyst (33) at the time of the start of internal combustion engine (10) can be suppressed.