A muffler heat protection system for a vehicle includes a muffler heat shield configured to extend circumferentially around a portion of a muffler, the muffler heat shield having a first end and a second end; a heat shield extension secured to the first end of the muffler heat shield; a double wall exhaust pipe including an inner exhaust pipe and an outer covering pipe disposed over the inner exhaust pipe, the outer covering pipe having a first end portion and a second end portion, and the inner exhaust pipe having a first end portion and a second end portion; wherein the second end portion of the outer covering pipe is welded to the muffler at a welded connection seam; and wherein the heat shield extension projects outward from the muffler heat shield over the welded connection seam.

A condensate discharge system for an exhaust gas measuring device. The condensate discharge system includes a condensate separator in which a positive pressure prevails, an outflow line in which atmospheric pressure prevails, a connecting line, and an intermediate reservoir in which the positive pressure prevails. The intermediate reservoir is arranged between the condensate separator and the outflow line and is directly connected to the condensate separator via the connecting line. The intermediate reservoir includes a float valve via which a condensate is dischargeable into the outflow line.

A condensate discharge system for an exhaust gas measuring device. The condensate discharge system includes a condensate separator in which a positive pressure prevails, an outflow line in which atmospheric pressure prevails, a connecting line, and an intermediate reservoir in which the positive pressure prevails. The intermediate reservoir is arranged between the condensate separator and the outflow line and is directly connected to the condensate separator via the connecting line. The intermediate reservoir includes a float valve via which a condensate is dischargeable into the outflow line.

A method for diagnosing a NOx sensor is provided. The method includes receiving data indicative of operating conditions of an engine or an aftertreatment system; determining, during a first period of time, that an amount of NOx output from the aftertreatment system satisfies a low NOx operating mode condition; determining, during a second period of time, that operating conditions for ammonia slip are present based on data regarding operation of the aftertreatment system; responsive to the determination that operating conditions for ammonia slip are present, determining that the amount of NOx output from the aftertreatment system satisfies a high NOx operating mode condition; comparing a difference between a minimum value from the first period of time and a maximum value from a second period of time to a diagnostic threshold; and responsive to the difference being less than the diagnostic threshold, setting an alert.

A method for diagnosing a NOx sensor is provided. The method includes receiving data indicative of operating conditions of an engine or an aftertreatment system; determining, during a first period of time, that an amount of NOx output from the aftertreatment system satisfies a low NOx operating mode condition; determining, during a second period of time, that operating conditions for ammonia slip are present based on data regarding operation of the aftertreatment system; responsive to the determination that operating conditions for ammonia slip are present, determining that the amount of NOx output from the aftertreatment system satisfies a high NOx operating mode condition; comparing a difference between a minimum value from the first period of time and a maximum value from a second period of time to a diagnostic threshold; and responsive to the difference being less than the diagnostic threshold, setting an alert.

Systems and apparatuses include a circuit structured to receive information indicative of a catalyst health, determine a catalyst health management criteria has been met based on the information, determine a catalyst loading based on the information and the catalyst health management criteria being met, and compare the determined catalyst loading to a predetermined loading limit. A notification circuit is coupled to the circuit and structured to provide a notification when the determined catalyst load exceeds the predetermined loading limit.

Systems and apparatuses include a circuit structured to receive information indicative of a catalyst health, determine a catalyst health management criteria has been met based on the information, determine a catalyst loading based on the information and the catalyst health management criteria being met, and compare the determined catalyst loading to a predetermined loading limit. A notification circuit is coupled to the circuit and structured to provide a notification when the determined catalyst load exceeds the predetermined loading limit.

A method for ascertaining an exhaust gas composition of an exhaust gas of an internal combustion engine with regard to an ammonia fraction and a nitrogen oxides fraction in an exhaust gas system including an SCR catalytic converter. The method includes detecting, using a sensor, a first signal whose magnitude is a function of the nitrogen oxides fraction of the exhaust gas upstream from the SCR catalytic converter, detecting using a sensor a second signal whose magnitude is a function of the ammonia fraction and the nitrogen oxides fraction of the exhaust gas downstream from the SCR catalytic converter, storing the two signals over an observation period, and ascertaining the ammonia fraction and optionally the nitrogen oxides fraction of the exhaust gas downstream from the at least one SCR catalytic converter using a calculation rule that uses the two signals during the observation period as input variables.

Defect detection systems include at least one nozzle for delivering a CO.sub.2 particulate fluid to an inlet end of a plugged honeycomb body. Defects in the honeycomb, if any, are determined by monitoring CO.sub.2 particulate flow at the outlet end of the honeycomb body. Methods for detecting defects in plugged honeycomb bodies are also disclosed.

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.