An upstream integrated value is an integrated value of a difference obtained by subtracting an upstream gas temperature at a starting point in time of integration from the upstream gas temperature after starting of the internal combustion engine. A downstream integrated value is an integrated value of a difference obtained by subtracting a downstream gas temperature at the starting point in time of the integration from the downstream gas temperature after the starting of the internal combustion engine. An anomaly diagnosing process obtains an anomaly determination result indicating that the exhaust purification device is in a removed state when a deviation between the upstream integrated value and the downstream integrated value is smaller than a reference level. The determination threshold is higher than a dew point.

A method includes calculating whether a quantity of the PMs accumulated in a PF is at or above a risk level at which damage to the PF is caused when regenerating the PF, calculating a driving condition index by accumulating a weighting factor for a driving condition under which there is a likelihood of causing the damage to the PF, when the amount of accumulated PMs is at or above the risk level; calculating a temperature index in accordance with a temperature of the PF and a PM index in accordance with the quantity of the accumulated PMs when the quantity of the accumulated PMs is at or above the risk level; calculating a degradation condition index considering the driving condition index, the temperature of the PF, and the quantity of accumulated PMs; and changing a regeneration period of the PF according to the degradation condition index.

A system includes a system includes an exhaust section which receives an exhaust flow of a gas turbine, where the exhaust section includes a catalyst assembly. The system includes an exhaust duct coupled to the diffuser section upstream of the catalyst assembly, where the exhaust duct extracts a return portion of the exhaust flow. The system includes a filter house coupled to the exhaust duct, where the filter house is receives a combined flow of an ambient air flow and the return portion. The system includes a return conduit coupled to the filter house and the exhaust section, where the return conduit is coupled to the exhaust section upstream of the exhaust duct. The return conduit directs the combined flow to the exhaust section, and the catalyst assembly receives a mixed flow including the exhaust flow and the combined flow.

Disclosed is an exhaust gas aftertreatment system (1) for a diesel engine, the exhaust gas aftertreatment system comprising: a treatment agent tank (2) for storing an exhaust gas treatment agent; a metering injection module (4), with the injection of the metering injection module (4) being controlled with a determined duty ratio signal according to a desired injection amount; a supply module (3) connected between the treatment agent tank (2) and the metering injection module (4) for supplying the exhaust gas treatment agent to the metering injection module (4); an exhaust gas treatment agent pipe (6) connected between the metering injection module (4) and the supply module (3); a pressure sensor for measuring the system pressure in the exhaust gas treatment agent pipe (6); and a controller (7); wherein the controller (7) is configured to receive a system pressure signal from the pressure sensor during injection of the metering injection module (4), and detect an injection abnormality of the metering injection module (4) based on at least a first amount, which represents an actual injection amount and is determined by the system pressure signal, and a second amount, which represents a theoretical injection amount and is determined by a corresponding duty ratio signal. A corresponding injection abnormality detection method is further disclosed. The injection abnormality detection method is simple and reliable.

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.

Methods and systems are provided for indicating a presence or absence of a source of degradation stemming from one of an intake manifold, exhaust system, or engine of an engine system. In one example, a method comprises rotating the engine unfueled and indicating the source of degradation based on both an intake air flow and an exhaust flow, as compared to baseline intake air flow and baseline exhaust flow. In this way, a source of degradation may be pinpointed, which may increase a lifetime of a vehicle engine system, reduce undesired emissions, and which may increase customer satisfaction resulting from shorter time spent on diagnosing such a source of degradation.

An automatic calibration method capable of adapting the set of conditions for performing hardware diagnostics, in an OBD system, with a view to optimizing the compromise between the number of diagnostics performed, in particular in order to comply with legislation relating to the ratio between the number of diagnostics performed on a component and the number of operating cycles, and the accuracy of the diagnostics.

A combustion system (100), a control module (104) for a combustion system (100) and a method of operating the combustion system (100) are disclosed. The method may be implemented by the control module (104) in the combustion system (100). The method comprises predicting an iced condition of the pressure sensor assembly (240); responsive to predicting the iced condition, controlling exhaust emissions without using a pressure parameter sensed with the pressure sensor assembly (240) in the iced condition; predicting a de-iced condition of the pressure sensor assembly (240); and responsive to predicting the de-iced condition, controlling the exhaust emissions using the pressure parameter sensed with the pressure sensor assembly (240) in the de-iced condition.

A failure determination apparatus for an oxygen concentration sensor disposed downstream of a catalyst provided in an exhaust system is provided for detecting a failure in the oxygen concentration sensor. The failure determination apparatus comprises: a failure determination device for determining a failure in the oxygen concentration sensor based on the length of a period when the output of the oxygen concentration sensor passes through a predetermined output section during enrichment control after a fuel cut mode of the internal combustion engine is released; a rich fuel supply amount calculation device for calculating the time average of an enriching fuel supply amount, relative to a fuel supply amount necessary for stoichiometric combustion, based on an actual fuel supply amount during the enrichment control; and a failure determination restriction device for restricting failure determination of the failure determination device based on the time average of the enriching fuel supply amount.

Methods and systems are provided for diagnostics of a gasoline particulate filter in an exhaust system after confirming that specific conditions are met including that an exhaust tuning valve is not degraded. In one example, a method may include indicating degradation of a hose coupled across a particulate filter responsive to a difference between a first differential pressure and a second differential pressure being greater than a threshold, the first differential pressure measured by a differential pressure sensor positioned in the hose responsive to a downstream exhaust tuning valve being fully open, the second differential pressure measured by the differential pressure sensor responsive to the exhaust tuning valve being fully closed.