An exhaust treatment system for a work vehicle includes a selective catalytic reduction (SCR) system having an SCR outlet for expelling treated exhaust flow therefrom, a flow conduit in fluid communication with the outlet, an exhaust sensor positioned within the flow conduit downstream of the outlet, and a flow mixer positioned upstream of the exhaust sensor. The flow mixer has an end wall defining sector openings circumferentially extending between first and second sector sides and radially between radially inner and outer sector ends. Moreover, the flow mixer has swirler vanes, where each of the swirler vanes extends circumferentially from the first sector side of a respective one of the sector openings and radially between radially inner and outer vane ends. Particularly, the radially outer vane end of each of the swirler vanes is spaced apart from the radially outer sector end of the respective one of the sector openings.

The present disclosure shows a system for checking a correct mounting of a plurality of sensors, in particular of sensors mounted in an engine system, comprising a controller configured for receiving signals from the plurality of sensors. The controller is configured to monitor a sequence and/or timing of the signals received from the sensors and to evaluate it with respect to a sequence and/or timing of a switching of a power supply to the sensors for checking the correct mounting of the sensors.

An exhaust system includes an exhaust gas-carrying pipe and a bypass to the exhaust gas-carrying pipe. The bypass has at least one inlet pipe and at least one outlet pipe. An exhaust gas sensor is arranged in the bypass between the inlet pipe and the outlet pipe in such a way that exhaust gas flowing through the bypass flows through the exhaust gas sensor. An accelerator accelerates the gas flow downstream of the exhaust gas sensor and is coupled to the outlet pipe. At least one inlet portion extends from the inlet pipe to the exhaust gas sensor, the flow cross-section of which is smaller than the flow cross-section of the inlet pipe and opens into an inlet of the exhaust gas sensor.

A catalytic converter system having oxygen storage materials is disclosed and methods for determining whether to reactivate oxygen storage materials and monitoring failure events of the oxygen storage materials are also disclosed.

An exhaust gas treatment system includes an exhaust gas pathway configured to receive exhaust gas from an internal combustion engine. The exhaust gas treatment system further includes a treatment element configured to reduce an emissions component of the exhaust gas, and a sample collector positioned within the exhaust gas pathway downstream of the treatment element. The sample collector includes a plurality of inlet openings spaced about a periphery of the exhaust gas pathway and configured to receive a sample of exhaust gas from the exhaust gas pathway, and an outlet in fluid communication with the plurality of inlet openings. A sensor located at the outlet of the sample collector is configured to measure a characteristic of the sample.

A method of manufacturing an on-board diagnostic (OBD) limit part and a method of testing to evaluate an OBD system. The method of manufacturing the OBD limit part includes introducing a contaminant to a selective catalytic reduction (SCR) catalyst and contacting the contaminant with the SCR catalyst for a selected period of time. The method of manufacturing utilizes a vessel, the contaminant, and the SCR catalyst. The OBD limit part is a combination of the contaminant and the SCR catalyst within the vessel. The method of testing to evaluate the OBD system includes collecting data related to an exhaust gas before and after the exhaust gas is exposed to the OBD limit part, collecting an indication provided by the OBD system, and comparing the data related to the exhaust gas and the indication provided by the OBD system. The method of testing to evaluate the OBD system utilizes a system that includes an exhaust gas source, a first and a second fluid path, the OBD limit part, and the OBD system.

Methods and systems are provided for adjusting an ammonia (NH.sub.3) sensor output using readings of a nitrogen oxide (NOx) sensor, the NOx sensor having a sensitivity factor to NH.sub.3. In one example, a method may include determining and updating a gain value of the NH.sub.3 sensor during zero NOx conditions to be used to calculate a corrected NH.sub.3 sensor output value, and determining and updating an offset value of the NH.sub.3 sensor during zero NH.sub.3 conditions to be used to zero the NH.sub.3 sensor during zero NOx conditions.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

Methods and systems for monitoring a NOx sensor for a NOx offset value are described. In one example, the NOx offset value may be based on a minimum NOx concentration observed over an entire drive of a vehicle. The NOx offset monitor may be inhibited in response to inferring or detecting a presence of NH.sub.3 in an exhaust system.

A method for determining a reference value of a presence of at least one substance (NO.sub.x) occurring in an exhaust gas stream of an internal combustion engine (101), wherein the at least one substance is subjected to exhaust treatment, the exhaust treatment being carried out in dependence on the reference value (Em.sub.ref; Em.sub.ref,1; Em.sub.ref,2) When the internal combustion engine (101) is started: accumulating the occurrence (Em.sub.ACC,1; Em.sub.ACC,2) of the at least one substance (NO.sub.x) downstream from the exhaust treatment during a first period, and determining whether to redetermine the reference value (Em.sub.ref; Em.sub.ref,1; Em.sub.ref,2) based on the accumulated occurrence (Em.sub.ACC,1; Em.sub.ACC,2) of the at least one substance (NO.sub.x).