A system and method for self-adjusting engine performance parameters in response to fuel quality variations that includes an exhaust sensor for measuring a level of carbon dioxide present in an exhaust manifold, at least one of a knock sensor and a cylinder pressure transducer for determining a location of peak pressure and a centroid, respectively, a controller in communication with the exhaust sensor and the at least one of the knock sensor and the cylinder pressure transducer, the controller correlating a methane number of the fuel used by the engine to a brake specific carbon dioxide value calculated using the level of carbon dioxide measured by the exhaust sensor and the at least one of the centroid and the location of peak pressure, and an adjusting mechanism, wherein the adjusting mechanism adjusts an engine performance parameter based on the determined methane number.

An exhaust purification device includes a PM filter and a differential pressure sensor for the PM filter, and calculates a first estimated amount PMf based on the operating state of the internal combustion engine and a second estimated amount PMc based on the differential pressure. The exhaust purification device performs an anomaly determination of the differential pressure sensor based on the state of the differential pressure sensor from stopping of the internal combustion engine to a startup thereof, and corrects the first estimated amount PMf based on the second estimated amount PMc when starting the internal combustion engine. The exhaust purification device calculates, as the PM deposition amount Pr, the larger value of the first and second estimated amounts, and starts a filter regeneration control of the PM filter when the PM deposition amount Pr is equal to or more than a first predetermined amount.

An exhaust system is provided that includes an exhaust aftertreatment unit, first and second exhaust pathway in communication with and upstream of the exhaust aftertreatment unit, a thermally activated flow control device operable in a first and second mode, and a thermal storage device. In the first mode, the flow control device permits exhaust to flow to the aftertreatment unit through the first pathway and inhibits flow through the second pathway. In the second mode, the flow control device permits exhaust flow to the aftertreatment unit through the second pathway and inhibits flow through the first pathway. The flow control device may switch between the first and second modes based on a change of temperature. The thermal storage device is within the second pathway, stores thermal mass, and provides thermal insulation to enable a catalyst of the aftertreatment unit to maintain a predetermined temperature for a predetermined time.

Methods and systems are provided for a particulate filter comprising a pretreatment. In one example, a method may include applying a pretreatment to an unused particulate filter, wherein the particulate filter is subjected to incomplete oxidation conditions following application of the pretreatment.

An engine device of this invention includes including a post-treatment device, provided in an exhaust passage of an engine, for purifying an exhaust gas from the engine. As the post-treatment device, a three-way catalyst is used. The engine device further includes a filter case including a filter body for catching deposits in the exhaust gas. The filter case is disposed, in a replaceable manner, upstream of the post-treatment device in the exhaust passage.

In a method and a device for diagnosing a differential pressure sensor of a particle filter of an internal combustion engine, where the differential pressure sensor is connected via a first pressure line to an exhaust-gas system upstream from the particle filter and via a second pressure line to the exhaust-gas system downstream from the particle filter and upstream from a rear muffler, a diagnosis of the first or second pressure lines is performed by evaluating a comparison of a differential pressure signal from a differential pressure sensor with modeled pressure values.

A control system for use in a fluid flow application includes a heater and a control device. The heater has at least one resistive heating element and the heater is operable to heat fluid. The control device determines at least one flow characteristic of a fluid flow based on a heat loss of the at least one resistive heating element and determines a mass flow rate of the fluid based on the at least one flow characteristic and a property of the at least one resistive heating element. And the property of the at least one resistive heating element includes a change in resistance of the at least one resistive heating element under a given heat flux density.

A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500 C. and about 800 C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

A controller is configured to perform a process of obtaining an exhaust pressure upstream of a filter inside an exhaust passage and an intake air amount detected by an air flowmeter, when the filter in which a deposition amount of particulate matter is a specified amount is referred to as a reference filter, a calculation process of calculating an exhaust pressure rate that indicates a ratio of the obtained exhaust pressure to an exhaust pressure at the reference filter for the obtained intake air amount, and a setting process of setting the exhaust pressure rate that is maintained at a specific value during engine operation.

A heater is provided that includes at least one resistive heating element having a material with a non-monotonic resistivity vs. temperature profile and exhibiting a negative dR/dT characteristic over a predetermined operating temperature range along the profile. The heater can include a plurality of circuits disposed in a fluid path to heat fluid flow.