Methods and system are provided to heat a catalyst of an after-treatment system for a vehicle. The after-treatment system comprises a heating module having a plurality of heating elements. Each of the plurality of heating elements is independently operable to provide thermal energy to the catalyst of the after-treatment system. One or more of the heating elements of the heating module are selectively operated to provide heat to the catalyst based on an operational parameter of the after-treatment system.

A selective catalytic reduction system control system (10) and method of its use include an ammonia (“NH.sub.3”) slip sensor (13) located within an interior space (27) of an exhaust stack (15) of a selective catalytic reactor (31), toward an inlet end (25) of the stack (15); a housing (17) located within the interior space of the exhaust stack; the housing including face panels 19; a nitrogen oxides (“NOx”) sensor (11) contained within an interior space (29) defined by the face panels of the housing, at least two of the face panels (19.sub.I, 19.sub.O) containing an oxidation catalyst; and a dosing controller (59) in communication with the NH.sub.3 and NOx sensors, the dosing controller including a microprocessor with dosing logic embedded thereon. The housing with oxidation catalyst acts as a linear box, isolating the NOx sensor from NH.sub.3 slip, linearizing the NOx sensor signal.

Provided is a muffler valve 1 that opens and closes an exhaust passage according to a pressure of an exhaust gas of an engine. A valve body 3 is swingably supported by a support shaft 4 with respect to a valve seat 2 having an opening 22, the valve body 3 is urged in a closing direction by a coil spring 5 externally inserted on the support shaft 4, a valve seat hook portion 23 is provided so as to embrace both ends of the support shaft 4 in a circumferential direction and is fixed to the support shaft 4, and a valve body winding portion 34 is provided so as to embrace the coil spring 5 in the circumferential direction from a direction opposite to the valve seat hook portion 23 and embrace the coil spring 5 over an entire length of the coil spring 5 in the circumferential direction. It is possible to prevent or suppress axial misalignment of the coil spring coaxially externally inserted on the support shaft for opening and closing the valve body as much as possible, and appropriately control the opening and closing of the valve body with high stability.

A non-transitory computer-readable medium having a NOx sensor purification instructions for a NOx sensor causes: an on-vehicle electronic computer mounted in the vehicle, when it comes to a predetermined purification time, to execute a start procedure to send a start command to perform a purification control to the control unit; and control unit, in response to the start command, to execute a purification procedure to perform the purification control which causes the current flowing in the reference pump cell from the reference pump current to be a purification pump current, which is set to a current value larger than the reference pump current.

A work vehicle includes an engine, a battery, an exhaust gas purification system or device, and a notification device. The exhaust gas purification system or device is capable of performing a purification process purifying exhaust gas of the engine, and operates with electric power from the battery and performs an end process. The notification device provides notification that the exhaust gas purification system or device is performing the end process or that the end process is completed.

Systems and methods for controlling a performance variable of an engine system are provided. An apparatus includes a response model circuit structured to apply a constraint to a response model that represents a relationship regarding a manipulated variable or a relationship between the performance variable and the manipulated variable. The apparatus further includes an optimization circuit structured to determine a target for the manipulated variable via the response model such that the target of the manipulated variable satisfies the constraint of the response model. The performance variable is indicative of performance of operation of the engine system and the manipulated variable is capable of affecting the performance variable. Operation of the engine system is adjusted based upon the target of the manipulated variable by controlling at least one of a fuel system or an air handling system of the engine system.

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

A vehicle includes an engine and a particulate filter that is situated to filter particulates from the exhaust fluid. A controller is configured to implement a sequence of particulate filter regeneration techniques including a first technique during an engine cold start condition, a second technique during a running engine idle condition, and a third technique during a driving condition. The controller is configured to determine whether particulate filter regeneration is desired, implement the first technique when particulate filter regeneration is desired, determine whether particulate filter regeneration is still desired after using the first technique, implement the second technique when regeneration is still desired after using the first technique, determine whether particulate filter regeneration is still desired after using the second technique, and implement the third technique when regeneration is still desired after using the second technique.

Systems and apparatuses include a circuit structured to receive information indicative of a catalyst health, receive information from a sensor array indicative of a catalyst activity, determine a catalyst health management criteria has been met based on the information, determine a catalyst age based on the information indicative of the catalyst activity and the catalyst health management criteria being met, compare the determined catalyst age to a predetermined age threshold, and provide a notification when the determined catalyst age exceeds the predetermined age threshold.

A control apparatus for an internal combustion engine includes an electronic control unit. The electronic control unit is configured to: execute increasing a temperature of an exhaust gas control apparatus at a second temperature increase speed as a regeneration control when the temperature of the exhaust gas control apparatus is in a second temperature range; control the temperature of an exhaust gas control apparatus during an idle operation so as to be equal to or smaller than the temperature of the exhaust gas control apparatus when the internal combustion engine enters an idle operation state as a temperature increase suppression control when the temperature of the exhaust gas control apparatus during a regeneration control is in the second temperature range and the internal combustion engine is in the idle operation state.