A device for exhaust gas aftertreatment in an internal combustion engine can be connected to an outlet of the internal combustion engine. The device comprises an exhaust gas system with an exhaust gas channel in which a three-way catalytic converter is arranged, and an exhaust gas burner with which hot burner exhaust gases can be fed into the exhaust gas channel at a feed point upstream from the three-way catalytic converter. The three-way catalytic converter is configured as a lambda probe catalytic converter and comprises a first catalyst volume and a second catalyst volume, whereby a lambda probe is arranged downstream from the first catalyst volume and upstream from the second catalyst volume, whereby the first catalyst volume has a lower oxygen storage capacity than the second catalyst volume. A method for exhaust gas aftertreatment in an internal combustion engine has such an exhaust gas aftertreatment device.

A sensor including a sensor element, a metallic shell, a terminal fitting, a cylindrical case, lead wires, a connector portion, and a cylindrical heat shield tube. The heat shield tube includes a first tube and a second tube. The second tube is disposed on a distal end side of the first tube and covers an outer surface of the rear end side of the case, while providing an overlapping portion that overlaps the first tube. A rear end side of the first tube is adjacent to the connector portion. A total length T of the heat shield tube and a length S of the overlapping portion satisfy T/10≤S≤T/5. Further, a length L1 of the first tube and a length L2 of the second tube satisfy T/2≤L2<L1.

An engine device of a working vehicle is capable of easily enhancing heat-retaining properties of a first case or a second case, and capable of easily forming, between an outer top plate and an inner top plate, a heat shield space in which a differential pressure sensor can be installed. The working vehicle includes an operation cabin on which an operator rides, the first case for removing particulate matter in exhaust gas in an engine, the second case for removing nitrogen oxide in exhaust gas of the engine, and a hood for covering an upper surface of the engine, and a top plate portion of the hood opposed to one or both of the first case and the second case placed on the upper surface of the engine is formed into a double structure from the outer top plate and the inner top plate.

Provided is an exhaust apparatus for a vehicle, being capable of performing a normal detection of a nitrogen oxide (NOx) concentration in exhaust gas without involving increase in the size and the cost. The exhaust apparatus includes an exhaust pipe having an upstream end connected to an aftertreatment device and a downstream end enclosing an exhaust port at a position higher than the upstream end, a NOx sensor to be retained in the exhaust pipe, and a water barrier wall provided inside the exhaust pipe. The water barrier wall has a shape to form a shield between the NOx sensor and the exhaust port while leaving a gas inlet that allows the exhaust gas to flow to the NOx sensor from the aftertreatment device through the gas inlet.

Systems and methods of reducing the emissions of vehicles having a spark ignited internal combustion engine are provided. When the exhaust temperature is less than a set point temperature, the oxygen concentration of the exhaust is increased as the exhaust passes from a first stage catalytic converter to a second stage catalytic converter. The increased oxygen content of the exhaust improves the removal efficiency of carbon monoxide and/or hydrocarbons at the second stage catalytic converter without (or with minimal) reforming nitrogen oxide compounds. The oxygen concentration of the exhaust is not increased when the exhaust temperature is greater than the set point temperature.

Systems and methods are described for sensing particulate matter in an exhaust system of a vehicle. An example system comprises a first outer tube with a plurality of intake apertures on an upstream surface, a second inner tube with a plurality of intake apertures on a downstream surface, and a particulate matter sensor placed within the second inner tube. The second inner tube may be positioned within the first outer tube such that a central axis of the second inner tube is parallel to a central axis of the first outer tube.

A method and apparatus forms an exhaust component that includes first and second substrates. An outer shell surrounds the first and second substrates. At least one sensor hole is formed in the outer shell at a location between the first and second substrates. A first end of the outer shell is surrounded with a plurality fingers to size the first end around the first substrate to a first diameter. The plurality of fingers includes an extended finger that is longer than the other fingers such that the extended finger at least partially covers the sensor hole during sizing of the first end. A second end of the outer shell is then surrounded by the fingers to size the second end around the second substrate to a second diameter. The extended finger at least partially covers the sensor hole during sizing of the second end.

An internal combustion engine comprises an exhaust purification catalyst and a downstream side air-fuel ratio sensor which is arranged at a downstream side of the exhaust purification catalyst. A control system can perform fuel cut control which stops the feed of fuel to the internal combustion engine during operation of the internal combustion engine, and, after the end of fuel cut control, performs post-return rich control which sets the exhaust air-fuel ratio to a rich air-fuel ratio. The control system correct the output air-fuel ratio of the downstream side air-fuel ratio sensor, based on a difference between the stoichiometric air-fuel ratio and the output air-fuel ratio in the output stabilization time period, which is a time period when the amount of change per unit time of the output air-fuel ratio of the downstream side air-fuel ratio sensor is a predetermined value or less, in the time period after the end of the fuel cut control and before the output air-fuel ratio of the downstream side air-fuel ratio sensor becomes a rich judged air-fuel ratio or less.

Methods and systems are provided for accurately inferring an exhaust temperature during steady-state and transient vehicle operation based on the duty cycle of an exhaust gas sensor heating element. A steady-state temperature is inferred based on an inverse of the duty cycle, and then adjusted with a transfer function that compensates for transients resulting from changes in vehicle speed, and load, and for the occurrence of tip-in and tip-out events. The inferred temperature can also be compared to a modeled temperature to identify exhaust temperature overheating conditions, so that mitigating actions can be promptly performed.

Methods of determining a desired sensor probe location in a closed loop emissions control (CLEC) system of a gas turbine engine are provided. One method includes determining, at different locations, a plurality of temperature contour profiles for exhaust flowing through an exhaust duct, selecting an emissions component entrained in the exhaust to be measured, and determining a desired sensor probe installation location based on the emissions component to be measured and based on the plurality of temperature contour profiles.