400 results about "Exhaust gas sensor" patented technology

A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air / fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air / lean mode: idle speed control, sensor diagnostics, air / fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Various systems and methods are described for an exhaust gas sensor coupled to an exhaust system of an engine. One example method comprises, during selected engine fueling conditions, alternating between applying first and second voltages to the sensor; and identifying an amount of alcohol in fuel injected to the engine based on sensor outputs at the first and second voltages.

An engine system for a vehicle is provided, comprising an internal combustion engine including an exhaust system; a first turbine including a first wastegate and arranged along a first branch of the exhaust system, a second turbine including a second wastegate and arranged along a second branch of the exhaust system; a first exhaust gas sensor arranged along the first branch of the exhaust system downstream of the first turbine and first wastegate; a second exhaust gas sensor arranged along the second branch of the exhaust system downstream of the second turbine and the second wastegate; and a control system configured to command the first and second wastegates to a closed or open position and to indicate one of said wastegates as unresponsive to said command in response to a temperature difference between the first and second branches indicated by the first and second exhaust gas sensors.

A deterioration failure diagnostic apparatus is provided for diagnosing an exhaust gas sensor disposed in an exhaust passage of an engine. The apparatus has a unit for generating a detecting signal and multiplying the generated signal to a first basic fuel injection amount to produce a second fuel injection amount. The apparatus includes a unit for calculating a feedback representative value based on feedback correction coefficients and multiplying the feedback representative value to the second fuel injection amount to produce a final fuel injection amount to be input to the engine. The apparatus includes a unit for extracting a frequency response corresponding to the detecting signal from an output of the exhaust gas sensor of the engine, the output being responsive to the calculated final fuel injection amount. A condition of the exhaust gas sensor is determined based on the extracted frequency response.

A deterioration failure diagnostic apparatus for an exhaust gas sensor has a higher detection precision and a wider detection range against the deterioration failure of the exhaust gas sensor. An exhaust gas sensor is disposed in an exhaust gas pipe of an internal-combustion engine for producing an output corresponding to components of exhaust gas of the engine. The apparatus has a device for producing a detecting signal, which is multiplied to a basic fuel injection amount used at a normal operation to produce a fuel injection amount to be used for determining a condition of the exhaust gas sensor. The apparatus includes a device for extracting a frequency response corresponding to the detecting signal from an output of the exhaust gas sensor. The output is in response to the calculated fuel injection amount. The condition of the exhaust gas sensor is determined based on the extracted frequency response.

Various systems and methods are described for an exhaust gas sensor coupled to an exhaust system of an engine. One example method comprises, during selected engine fueling conditions, alternating between applying different voltages to the sensor; and identifying an amount of alcohol in fuel injected to the engine based on sensor outputs at the different voltages.

A deterioration detecting apparatus for an exhaust gas sensor of an internal combustion engine, the exhaust gas sensor including a sensor element and a heater that heats the sensor element, computes a first sensor characteristic parameter, which is related to a characteristic of the sensor element, by estimating an interchange state of thermal energy between the sensor element and a periphery of the sensor element. The deterioration detecting apparatus senses impedance of the sensor element. The deterioration detecting apparatus computes a second sensor characteristic parameter, which is related to the characteristic of the sensor element, based on the sensed impedance. The deterioration detecting apparatus determines a degree of deterioration of the exhaust gas sensor by comparing the first sensor characteristic parameter and the second sensor characteristic parameter.

The invention relates to a method for diagnosing a selective catalytic reduction (SCR) catalyst (5) of an exhaust aftertreatment system (1) of an internal combustion engine (2). The exhaust aftertreatment system (1) comprises a SCR catalyst (5); an reductant injector (9) arranged upstream of the SCR catalyst (5) for injecting a reductant into an exhaust gas; and an exhaust gas sensor (11) arranged downstream of the SCR catalyst (5). The exhaust gas sensor (11) is cross-sensitive to nitrogen oxide (NOx) and ammonia (NH3) present within the exhaust gas leaving the SCR catalyst (5). The method comprises the steps of: ensuring that a SCR catalyst NH3 storage level is substantially below the current maximal NH3 storage capacity of the SCR catalyst (5); initiating over-injection of reductant by the injector (9); stopping reductant injection upon registering, by the exhaust gas sensor (11), an increasing NOx+NH3 emission level and an NOx+NH3 emission level exceeding a predefined threshold value, and when the reduction injection is stopped recording an output signal of the exhaust gas sensor (11) until an indication of a minimal or negligible SCR catalyst NH3 storage level is determined; and calculating a SCR catalyst NH3 storage capacity on the basis of the recorded output signal.