Methods for monitoring and/or regenerating a selective catalytic reduction particulate filter (SCRF) are provided. The SCRF comprises a porous filter substrate and a catalytic composition capable of reducing NOx applied thereto. Methods include determining a SCRF pressure differential (dP) and determining the SCRF soot loading using a 1st SCRF dP map if the SCRF has not been degreened, or a 2nd SCRF dP map if the SCRF has been degreened. The SCRF has been degreened if one or more of a degreening cumulative time and temperature threshold has been achieved and a filter regeneration count threshold has been achieved. The 1st and 2nd SCRF dP maps correlate SCRF dP and one or more of SCRF temperature, exhaust mass flow, and exhaust volumetric flow to a SCRF soot loading. The method can optionally further include initiating a filter regeneration if the determined SCRF soot loading is above a soot loading threshold.

Methods and systems are provided for diagnosing degradation of an exhaust valve coupled to an engine cylinder. In one example, a method may include, routing compressed air from an electric booster into a cylinder with the intake valve of the cylinder open and the exhaust valve closed, and indicating degradation of the exhaust valve based on an exhaust airflow relative to a baseline airflow.

A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.

Exhaust systems for handling multiple effluent streams are described. Some embodiments include pressure drops to prevent perturbations from one effluent source from affecting a second effluent source. Some embodiments incorporate an exhaust assembly with multiple inlets and pumps and a single outlet. The exhaust assembly includes shared auxiliary components like purge and cooling systems.

Methods and systems are provided for diagnosing a source of degradation in an exhaust system of a vehicle. In one example, a method may include actuating an electric turbocharger to rotate in a first direction to evaluate integrity of an exhaust pipe of the exhaust system and rotation the turbocharger in a second direction to assess an exhaust manifold of the exhaust system, after an engine of the vehicle is turned off. Pressures generated in the exhaust system are compared to thresholds based on barometric pressure and/or turbocharger speed.

A control system for use in a fluid flow application is provided. The control system includes a heater having at least one resistive heating element. The heater is adapted to heat the fluid flow. The control system further includes a control device that uses heat loss from at least one resistive heating element to determine flow characteristics of the fluid flow.

A method is provided for ascertaining a NO.sub.x concentration and an NH.sub.3 slip downstream from an SCR catalytic converter of an internal combustion engine of a vehicle. State variables of an internal combustion engine as first input variables and an updated NH.sub.3 fill level of the SCR catalytic converter as a second input variable cooperate with at least one machine learning algorithm or at least one stochastic model. The at least one machine learning algorithm or at least one stochastic model calculates the NO.sub.x concentration and the NH.sub.3 slip downstream from the SCR catalytic converter as a function of the first input variables and the second input variables and output the same as output variables.

An emissions sensor health monitor can acquire nitrogen oxide (NOx)-in values measured by an input emissions sensor of the machine and NOx-out values measured by an output emissions sensor of the machine. The emissions sensor health monitor can identify samples of the machine channel data that meet criteria associated with an idle operating condition of an engine of the machine, and determine NOx delta values for the samples. The emissions sensor health monitor can determine that the NOx delta values are above a preset acceptable threshold for at least a threshold time period, and in response perform one or more responsive actions.

An exhaust purification system of an internal combustion engine comprises a filter trapping particulate matter in exhaust gas, a differential pressure sensor detecting a differential pressure before and after the filter or a differential pressure between a pressure in the exhaust passage and an atmospheric pressure, a temperature sensor detecting a temperature of exhaust gas, and a deposition calculating part configured to calculate an amount of particulate matter deposited at the filter. The deposition calculating part is configured to calculate a first estimated value of an amount of the particulate matter based on the differential pressure, calculate a second estimated value of an amount of the particulate matter based on an amount of increase of temperature of the exhaust gas, and calculate an amount of the particulate matter based on the first estimated value and the second estimated value.

When atmospheric pressure (Pa) which varies according to altitude is higher than a predetermined pressure threshold (Path) during idle operation in which catalyst warm-up request is issued, an intake pressure is controlled, through a throttle valve (19), to an intake pressure at which an intake air amount required to promote the warm-up of a catalyst converter (26) is obtained. When the atmospheric pressure (Pa) is lower than the predetermined pressure threshold (Path), the intake pressure is controlled, through a throttle valve (19), to an intake pressure (PaPb) at which a differential pressure (Pb) required by a brake booster (8) is obtained. Accordingly, negative pressure in the brake booster (8) can be secured while promoting the warm-up of the catalyst during the idle operation.