An internal combustion engine arrangement includes an internal combustion engine, a catalytic converter, and a controller. The controller is configured to determine a maximum H.sub.2 production capacity of the catalytic converter. The catalytic converter is arranged downstream of the internal combustion engine. The controller is configured and adapted to determine the maximum H.sub.2 production capacity of the catalytic converter based on a first function that correlates an H.sub.2 production of the internal combustion engine with first internal combustion engine parameters.

A control device for an internal combustion engine including an upstream cleaning device and a downstream cleaning device that are provided in an exhaust gas passage and a temperature sensor that detects a temperature of exhaust gas between the upstream cleaning device and the downstream cleaning device is provided. The control device includes a first temperature estimating unit configured to estimate a temperature of the downstream cleaning device from the temperature of exhaust gas detected by the temperature sensor and a second temperature estimating unit configured to estimate a temperature of the downstream cleaning device without using the temperature of exhaust gas detected by the temperature sensor. An abnormality determining process for the upstream cleaning device is performed when at least the temperature of the downstream cleaning device estimated by the second temperature estimating unit is equal to or greater than a predetermined threshold value.

A method for checking operability of a first metering unit includes sending a control signal to a second metering unit to dispense a second quantity; comparing the quantity dispensed with the second quantity; sending a control signal to a second metering unit to introduce a third quantity; detecting the pressure drop caused by the introduction of the third quantity; sending a control signal to the first metering unit to introduce a first quantity; detecting the pressure drop caused by executing the control signal to introduce the first quantity; and ascertaining that the first metering unit is not functioning correctly if a difference between the pressure drop detected as a result of the execution of the control signal to introduce the first quantity and the pressure drop detected as a result of the execution of the control signal to introduce the third quantity is above a threshold.

A method for checking operability of a first metering unit includes sending a control signal to a second metering unit to dispense a second quantity; comparing the quantity dispensed with the second quantity; sending a control signal to a second metering unit to introduce a third quantity; detecting the pressure drop caused by the introduction of the third quantity; sending a control signal to the first metering unit to introduce a first quantity; detecting the pressure drop caused by executing the control signal to introduce the first quantity; and ascertaining that the first metering unit is not functioning correctly if a difference between the pressure drop detected as a result of the execution of the control signal to introduce the first quantity and the pressure drop detected as a result of the execution of the control signal to introduce the third quantity is above a threshold.

A method that determines a cause for the impaired performance of a catalytic configuration of the exhaust gas of a combustion engine (231), the method including determining (s410) a course of a NOx-conversion ratio; determining (s420) a prevailing temperature of the catalytic configuration; increasing (s430) the temperature of the catalytic configuration from a prevailing temperature below a predetermined temperature value (Te) to a temperature (TSred) above the predetermined temperature value above which sulphur is removed from the catalytic configuration; and/or decreasing (s440) the temperature of the catalytic configuration from a prevailing temperature (TSred) above the predetermined temperature value (Te) to a temperature below the predetermined temperature value so as to impair the performance of the catalytic configuration in case sulphur is present; and determining (s450) one cause out of a set of causes on the basis of the course of the NOx-conversion ratio thus determined.

A method that determines a cause for the impaired performance of a catalytic configuration of the exhaust gas of a combustion engine (231), the method including determining (s410) a course of a NOx-conversion ratio; determining (s420) a prevailing temperature of the catalytic configuration; increasing (s430) the temperature of the catalytic configuration from a prevailing temperature below a predetermined temperature value (Te) to a temperature (TSred) above the predetermined temperature value above which sulphur is removed from the catalytic configuration; and/or decreasing (s440) the temperature of the catalytic configuration from a prevailing temperature (TSred) above the predetermined temperature value (Te) to a temperature below the predetermined temperature value so as to impair the performance of the catalytic configuration in case sulphur is present; and determining (s450) one cause out of a set of causes on the basis of the course of the NOx-conversion ratio thus determined.

An apparatus for heating an exhaust gas after-treatment unit in a vehicle has, as a drive source, both a combustion engine and an electric motor. The apparatus includes: a honeycomb body configured for exhaust gas to flow therethrough, the honeycomb body having a hollow, through which hollow the exhaust gas flows; and at least one electric heating element arranged in the hollow so as to heat the honeycomb body. The honeycomb body includes a plurality of metal foils stacked one on top of the other, which metal foils form between them a plurality of flow channels, through which a flow can pass along an axial direction, wherein the hollow of the honeycomb body extends in a radial direction, in which the at least one heating element is accommodated.

A system, apparatus, and method are provided for preventing the accumulation of particulate matter such as combustion soot on sensors positioned in exhaust gas conduits of internal combustion engines. In an embodiment, the apparatus includes a device for deflecting soot deposits from sensor surfaces. In an embodiment, the apparatus includes a device employing a surface acoustic wave generator for dislodging soot accumulation or measuring soot accumulations to trigger burn-off events. In an embodiment, an injector injects pressurized bursts of gas toward a sensor surface to dislodge particulate matter. In an embodiment, charged electrodes attract charged particles of soot from the exhaust gas flow to form deposits that are then subject to burn-off events.

A system, apparatus, and method are provided for preventing the accumulation of particulate matter such as combustion soot on sensors positioned in exhaust gas conduits of internal combustion engines. In an embodiment, the apparatus includes a device for deflecting soot deposits from sensor surfaces. In an embodiment, the apparatus includes a device employing a surface acoustic wave generator for dislodging soot accumulation or measuring soot accumulations to trigger burn-off events. In an embodiment, an injector injects pressurized bursts of gas toward a sensor surface to dislodge particulate matter. In an embodiment, charged electrodes attract charged particles of soot from the exhaust gas flow to form deposits that are then subject to burn-off events.

Methods and systems to control a temperature of a selective catalytic reduction catalyst are disclosed. In one example, a diverter valve that includes two butterfly valves that are coupled together via a shaft is adjusted to control a temperature at an inlet of the selective catalytic reduction catalyst so that the selective catalytic reduction catalyst may operate efficiently.