Methods and systems are provided for estimating a PCV flow to an engine based on the output of an exhaust gas oxygen sensor. During DFSO conditions, a reference voltage of the sensor is modulated initially with an intake throttle open and then with the intake throttle closed. PCV flow leaking past the piston valves in an aging engine, as well as an ambient humidity estimate, are inferred based on the outputs of the sensor during the modulating with the intake throttle open and closed.

A method comprising adjusting a fuel injection amount based on a fractional oxidation state of a catalyst, the fractional oxidation state based on reaction rates of grouped oxidant and reductant exhaust gas species throughout a catalyst and a low-dimensional physics-based model derived from a detailed two-dimensional model to obtain a one-dimensional model averaged over time and space that accounts for diffusion limitations in the washcoat and accurately predicts emissions during cold start.

The gas sensor is equipped with a sensor device, a plurality of electrode springs contacting with electrodes and of the sensor device, an insulator retaining the electrode springs, and a plurality of leads connected to the respective electrode springs. Each of the electrode springs includes a retained portion retained by the insulator and a contact portion which is bent and inclined from the retained portion toward a front end side of the sensor device in the lengthwise direction. The contact portion is elastically deformed in contact with the electrode. Each of the electrode springs also includes a bent portion between the contact portion and the retained portion. The bent portion constitutes a base end of the contact portion and is oriented toward the base end side of the gas sensor in the lengthwise direction, thereby enabling the length of the sensor device to be decreased and improving the heat resistance of the electrode springs.

A method is provided for detecting fuel discharge from a lubricant in a housing of an internal combustion engine. A first lambda deviation is measured by a lambda sensor for a first mass air flow supplied in an intake tract of the engine. A second lambda deviation is measured by the lambda sensor for a second mass air flow that differs from the first mass air flow, and is supplied in an intake tract of the engine. An actual comparative value is calculated from the measured first and second lambda deviations. A desired comparative value indicative of the fuel discharge is calculated from a first desired lambda deviation for the first mass air flow, and a second desired lambda deviation is calculated for the second mass air flow. The fuel discharge is detected based on a comparison of the actual comparative value and the desired comparative value.

Provided is a method for accurately diagnosing a degree of degradation of an oxidation catalyst. A target gas detecting element configured to output an electromotive force corresponding to a concentration of a target gas is provided downstream of a catalyst in an exhaust path of an internal combustion engine. A sum of change amounts of an electromotive force in a time-variable profile thereof after the introduction of a gas atmosphere for diagnosis into the catalyst is set as a diagnosis index value. The gas atmosphere has been intentionally created in the engine and includes a target gas having a concentration higher than the concentration of a target gas during a steady operation state of the engine. The index value is then compared with a threshold corresponding to the temperature of the catalyst to diagnosis whether degradation exceeding an acceptable degree has occurred in the catalyst.

An abnormality detection device determines abnormality in an exhaust gas sensor, disposed in an exhaust passage of an engine to detect a component in exhaust gas. The abnormality detection device includes: a responsiveness determination unit configured to calculate responsiveness of the exhaust gas sensor on the basis of a timewise change of output values of the exhaust gas sensor; and an abnormality determination unit configured to determine that the exhaust gas sensor has abnormality when the responsiveness calculated by the responsiveness determination unit is lower than a predetermined responsiveness threshold. The abnormality determination unit determines if the exhaust gas sensor has abnormality, excluding an excluded period during which a slope of the output values becomes zero or is inversed with respect to a preceding trend of the timewise change while the output values of the exhaust gas sensor timewisely change between a predetermined first and second determination values.

A method for a two-point lambda sensor includes, changing a composition of an air/fuel mixture supplied to an internal combustion engine from a predefined lambda value to lambda=1, determining a delay time of the voltage value reaching a value corresponding to the lambda=1, again changing the composition of the air/fuel mixture from the predefined lambda value to lambda=1, determining a characteristic of the changing performed in the second regulation based on the delay time, determining an actual value of lambda on an actual voltage-lambda characteristic curve of the two-point lambda sensor that corresponds to the predefined lambda value which is in reference to a reference voltage-lambda characteristic curve based on the determined characteristic, and identifying a voltage offset between the characteristic curves based on a deviation of the actual value from the predefined value.

A system for combusting volatile vapors includes a carburetor having intake valves for receiving base fuel from a fuel source, ambient combustion air, and volatile vapors from a vapor source. A plurality of sensors measure and generate sensor data based on a respective plurality of physical properties associated with the carburetor and associate combustion engine operation. One or more programmable controllers receive the sensor data and control the intake valves to regulate respective ratios of the fuel, air, volatile vapors drawn through the carburetor based on the received sensor data. To increase the burn of volatile vapors, an engine loading system automatically operated by the controller(s) applies an automatically adjustable braking load on the engine. The load level applied is based on the sensor data and commensurate with maintaining stable engine running conditions. The loading system decreases time necessary to remediate a site.

Disclosed is a sensor, including: a sensor body having a cylindrical case and a sensor element accommodated in the case; a seal member disposed in a rear end part of the case; lead wires electrically connected to the sensor element and extending from inside to outside of the casing through the seal member; and a cylindrical heat shield tube retained to an outer surface of the case and extending rearward from the case so as to circumferentially surround the seal member and parts of the lead wires, characterized in that: the sensor further includes a cylindrical tube cap made of an elastic material and arranged to restrict a rearward movement of the heat shield tube; the tube cap has formed therein at least one lead wire insertion hole through which the lead wires are inserted; and the tube cap is reduced in diameter and held to the lead wires.

An evaluation and control unit for operating a wideband lambda sensor that has at least two electrical lines, the evaluation and control unit having at least two electrical terminals for electrical connection to the electrical lines of the wideband lambda sensor. Each of the electrical terminals has assigned to it a respective electrical switch via which each terminal is capable of being individually connected to at least one defined electrical potential. Each switch is voltage-resistant against the maximum short-circuit voltage that is to be expected at the respective terminal in case of fault. In addition, a method is described for the line-specific short-circuit diagnosis of the wideband lambda sensor (pinpointing).