A method for monitoring emissions in the exhaust gas of an internal combustion engine in a vehicle, comprising carrying out (520) multiple successive emission measurements for at least one component in the exhaust gas, wherein each of the emission measurements is respectively performed after a driving distance of predefined length is covered by the vehicle; storing (540) a distance-related emission value (E.sub.i), which was obtained (530) on the basis of the measurement, in a memory element (42, 200, 400) for each of the emission measurements; and forming (550) a smoothed emission level for a current point in time on the basis of multiple of the previously stored distance-related emission values, wherein more recent emission values are taken into consideration more strongly than emission values lying farther back in time in the formation of the smoothed emission level.

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.

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.

Disclosed is a method for use in a process of selective catalytic reduction (SCR) after-treatment of an exhaust gas of an exhaust gas stream, where the process comprises the reduction of nitrogen oxides of the exhaust gas stream through the use of a reducing agent derived from an additive. The disclosed method comprises: defining an integrand to be the difference between the rate of injection of the additive and the rate of evaporation of the additive to the reducing agent multiplied by a coefficient (s), wherein the value of the coefficient (s) is between zero and one; producing an integral controller output proportional to the integral of the integrand with time; requesting a countermeasure based on the integral controller output to counteract solid deposits derived from the additive.

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).

A method and system for detecting whether a pressure line in a diesel exhaust fluid (DEF) delivery system has an obstruction. The system includes an electronic control unit with an electronic processor that is configured to receive an unfiltered pressure signal from a pressure sensor; to electronically filter the unfiltered pressure signal to determine a dosing pressure signal; to determine an integrated value based on the dosing pressure signal; and to determine whether the pressure line is obstructed by comparing the integrated value with a predetermined threshold.

A process is provided for regenerating an exhaust gas after-treatment device in an exhaust line of an internal combustion engine arrangement, the exhaust line including a particle filter. The process includes identifying when soot loading of the particle filter exceeds a predetermined level. After that, temperature of exhaust gases at the particle filter is maintained within a first temperature range until at least one of a predetermined period of time has lapsed or a determination is made that soot loading of the particle filter is below the predetermined level. After that, the temperature of the exhaust gases at the particle filter is increased to within a second temperature range above the first temperature range. An internal combustion engine arrangement is also disclosed.

A system, method, and apparatus for decreasing harmful emissions is provided. The system includes an aftertreatment system comprising an exhaust conduit that directs exhaust gas from an engine system; a heater coupled to the aftertreatment system and configured to provide heat; and a controller coupled to the heater. The controller is configured to: determine whether the engine system is idling; in response to determining that the engine system is idling, determine whether a conversion efficiency of the engine system is greater than a threshold value; in response to determining that the conversion efficiency is greater than the threshold value, determine whether a temperature regarding the aftertreatment system is greater than a threshold temperature; and in response to determining that the temperature of the aftertreatment system is greater than the threshold temperature, at least one of disable or partially disable the heater.

A method of calculating a nitrogen oxide (NOx) mass reduced from a lean NOx trap (LNT) during regeneration includes calculating a C3H6 mass flow used to reduce the NOx among a C3H6 mass flow flowing into the LNT of an exhaust purification device, calculating a NH3 mass flow used to reduce the NOx among a NH3 mass flow generated in the LNT, calculating a reduced NOx mass flow based on the C3H6 mass flow used to reduce the NOx and the NH3 mass flow used to reduce the NOx, and calculating the reduced NOx mass by integrating the reduced NOx mass flow over a regeneration period.

An exhaust purification system comprising an exhaust purification catalyst, a downstream side air-fuel ratio sensor, and a control device performing air-fuel ratio control for controlling an air-fuel ratio of exhaust gas and abnormality diagnosis control for diagnosing the downstream side air-fuel ratio sensor. In the air-fuel ratio control, the control device alternately and repeatedly switches the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst between a rich air-fuel ratio and a lean air-fuel ratio. In the abnormality diagnosis control, the control device judges that the downstream side air-fuel ratio sensor has become abnormal when the air-fuel ratio of the exhaust gas is made the rich air-fuel ratio by the air-fuel control and the output air-fuel ratio of the downstream side air-fuel ratio sensor changes from an air-fuel ratio richer than a predetermined lean judged air-fuel ratio to an lean air-fuel ratio.