A sensor device includes a substrate, a sensing layer formed over the substrate, and a cover layer at least partially covering the sensing layer and protecting the sensing layer. The cover layer is a porous material or has a plurality of openings.

An internal combustion engine has a humidity sensor that is disposed in an intake passage of the internal combustion engine, a temperature sensor configured to detect an intake air temperature in a position of the humidity sensor, and a controller configured to correct an offset error of the sensor value by adding a correction value to the sensor value. The controller is configured to acquire the intake air temperatures respectively at a plurality of timings in a process of the intake air temperature changing, acquire the sensor values at the respective plurality of timings, calculate values excluding influences of temperature differences of the intake air temperatures from the respective sensor values as humidity index values respectively, and determine a correction value so that a variation degree of the humidity index values becomes small.

A vehicle particulate matter contamination recovery system includes a particulate matter filter receiving exhaust gas from an engine. A particulate matter sensor is positioned downstream of the particulate matter filter, the particulate matter sensor collecting a non-combustible contaminant on a circuit of the particulate matter sensor and generating a current indicating presence of the non-combustible contaminant. A total volume of water collected during multiple cold start operations of the engine is passed onto the sensor acting to at least partially dissolve the non-combustible contaminant. The particulate matter sensor is operated in a remedial action mode of operation having no voltage applied to the circuit of the particulate matter sensor until a quantity of the cold start operations corresponding to the total volume of water is reached.

A diagnostic system (10) is provided and includes a sensor (24) disposed downstream from an exhaust gas aftertreatment system. Also included in the diagnostic system (10) is a central diagnostic unit (35) configured to diagnose a condensation condition associated with the sensor (24) for mitigating a sensor failure due to water condensation on the sensor (24), the central diagnostic unit (35) performing the diagnosis on the condensation condition based on water storage and release information related to a component of the exhaust gas aftertreatment system. The sensor (24) is activated based on the water storage and release information.

A CO.sub.2 mass estimation system includes: an acquisition element acquiring detected values in accordance with concentrations of oxygen, H.sub.2O, and CO.sub.2 contained in an engine exhaust gas output from a gas sensor; a setting element setting an air-fuel ratio of a mixture; and a calculation element calculating the mass of CO.sub.2 contained in the exhaust gas, wherein the calculation element calculates the concentrations of oxygen, H.sub.2O, and CO.sub.2 contained in the exhaust gas based on the sensor detected values, acquires concentrations of oxygen and H.sub.2O in air and the air-fuel ratio, calculates a composition ratio of at least C atoms contained in fuel based on the concentrations in the exhaust gas, the concentrations in the air, and the air-fuel ratio, and estimates the mass of CO.sub.2 contained in the exhaust gas based on the composition ratio and the amount of injection of the fuel into the engine.

The disclosure relates to a method for determining the icing condition of a component of the exhaust-gas system of a motor vehicle that is not arranged directly in the exhaust-gas mass flow and/or of the feed line of the component. The method includes: determining a water quantity actually present in the component and in the feed line thereof and the state of aggregation of the water quantity; determining an energy quantity required for deicing and for volatilizing the water quantity; and determining an energy quantity supplied for deicing and for volatilizing the water quantity by radiated heat from components arranged directly in the exhaust-gas mass flow of the exhaust-gas system of the motor vehicle to the surroundings. The method also includes determining the icing condition of the component by comparing the energy quantity supplied for deicing and for volatilization with the energy quantity required for deicing and for volatilization.

Disclosed is an exhaust system for a vehicle having an exhaust passageway through which products of combustion from the engine pass through and out to atmosphere, which exhaust system has a bead portion formed in the exhaust passageway with one more holes in the lower portion thereof through which at least a portion of the rain which has entered the interior of the exhaust passageway may flow out from the interior of the exhaust passageway prior to flowing downward to a lower portion of the exhaust passageway at which the rain is undesirable.

A vehicle particulate matter contamination recovery system includes a particulate matter filter receiving exhaust gas from an engine. A particulate matter sensor is positioned downstream of the particulate matter filter, the particulate matter sensor collecting a non-combustible contaminant on a circuit of the particulate matter sensor and generating a current indicating presence of the non-combustible contaminant. A total volume of water collected during multiple cold start operations of the engine is passed onto the sensor acting to at least partially dissolve the non-combustible contaminant. The particulate matter sensor is operated in a remedial action mode of operation having no voltage applied to the circuit of the particulate matter sensor until a quantity of the cold start operations corresponding to the total volume of water is reached.

The NOx catalyst is irradiated with an electromagnetic wave, a resonance frequency and a ratio of a reception power to an oscillation power at the time of the irradiation are detected, and an upper limit value of a change amount of the resonance frequency or an upper limit value of a change amount of the ratio at which the NOx catalyst is diagnosed to be abnormal is determined from a change amount of the resonance frequency and a change amount of the ratio until water is adsorbed on all acid sites included in the NOx catalyst, and a change amount of the resonance frequency and a change amount of the ratio until ammonia is adsorbed on all acid sites included in the NOx catalyst, when it is supposed that the NOx catalyst is in a state of being on the borderline between normal and abnormal.

Disclosed is an exhaust system for a vehicle having an exhaust passageway through which products of combustion from the engine pass through and out to atmosphere, which exhaust system has a bead portion formed in the exhaust passageway with one more holes in the lower portion thereof through which at least a portion of the rain which has entered the interior of the exhaust passageway may flow out from the interior of the exhaust passageway prior to flowing downward to a lower portion of the exhaust passageway at which the rain is undesirable.