Abstract: Methods of treating exhaust in a vehicle, and exhaust systems for a vehicle, are disclosed. Example methods may include providing a catalytic converter in an exhaust tailpipe and an oxygen sensor downstream of the catalytic converter. The catalytic converter may be configured to reduce a concentration of a nitrogen oxide (NOx) present in an exhaust flow through the catalytic converter. The method further includes predicting an increase in an oxygen concentration within the catalytic converter based upon at least one or more real-time vehicle operating parameters, wherein the increase is predicted before a corresponding increase in oxygen concentration is measured by the downstream oxygen sensor. The method may also include adjusting an air-fuel ratio of an engine of the vehicle based upon the predicted increase in oxygen concentration, thereby at least partially preventing the corresponding increase in the oxygen concentration.

Abstract: According to one or more embodiments of the technical solutions described herein, a control system in a motor vehicle that includes an internal combustion engine includes an oxygen sensor, and an oxygen sensor diagnosis module to diagnose the oxygen sensor. The oxygen sensor diagnosis includes performing an intrusive rich-to-lean diagnostic for the oxygen sensor, and detecting a lean-to-rich diagnostic event. In response, the diagnosis includes performing a passive lean-to-rich diagnostic for the oxygen sensor, the lean-to-rich diagnostic event comprising a fuel enrichment.

Abstract: A system according to the principles of the present disclosure includes a diagnostic execution module and a diagnostic disabling module. The diagnostic execution module diagnoses a fault in at least one of an oxygen sensor and a catalytic converter based on input received from the oxygen sensor. The diagnostic disabling module disables the diagnosing based on at least one of a temperature of the catalytic converter and a mass flow rate of air flowing through the catalytic converter.

Abstract: A diagnostic system for an engine includes a stage transition module and a control module. The stage transition module generates a command signal based on a fuel control signal. The command signal commands a fuel system of the engine to intrusively transition between rich and lean states during a diagnostic test that includes first, second, and third stages. The first, second, and third stages are defined based on transitions between the rich and lean states. The control module during the second and third stages detects: an error with a first oxygen sensor based on a comparison between the command signal and a first oxygen signal from the first oxygen sensor; an error with a second oxygen sensor based on a second oxygen signal from the second oxygen sensor; and an error with a catalytic converter based on the first and second oxygen signals and a manifold absolute pressure signal.

Abstract: A system according to the principles of the present disclosure includes a diagnostic execution module and a diagnostic disabling module. The diagnostic execution module diagnoses a fault in at least one of an oxygen sensor and a catalytic converter based on input received from the oxygen sensor. The diagnostic disabling module disables the diagnosing based on at least one of a temperature of the catalytic converter and a mass flow rate of air flowing through the catalytic converter.

Abstract: An engine control system includes an oxygen (O2) sensor diagnostic module that diagnoses an O2 sensor and requests a minimum air per cylinder (APC). A throttle actuator module controls a throttle to adjust a mass air flow based on the minimum APC.

Abstract: A diagnostic system for an engine includes a stage transition module and a control module. The stage transition module generates a command signal based on a fuel control signal. The command signal commands a fuel system of the engine to intrusively transition between rich and lean states during a diagnostic test that includes first, second, and third stages. The first, second, and third stages are defined based on transitions between the rich and lean states. The control module during the second and third stages detects: an error with a first oxygen sensor based on a comparison between the command signal and a first oxygen signal from the first oxygen sensor; an error with a second oxygen sensor based on a second oxygen signal from the second oxygen sensor; and an error with a catalytic converter based on the first and second oxygen signals and a manifold absolute pressure signal.

Abstract: A diagnostic system for an exhaust system including a catalyst and a post-catalyst oxygen sensor is provided. The system generally includes a fuel control module that commands fuel to transition from a rich condition to a lean condition and that commands fuel to transition from the lean condition to the rich condition. A first diagnostic module monitors the post-catalyst oxygen sensor during the transition from the rich condition to the lean condition. A second diagnostic module monitors the catalyst during the transition from the lean condition to the rich condition.

Abstract: An engine control system includes an oxygen (O2) sensor diagnostic module that diagnoses an O2 sensor and requests a minimum air per cylinder (APC). A throttle actuator module controls a throttle to adjust a mass air flow based on the minimum APC.

Abstract: A diagnostic system for an exhaust system including a catalyst and a post-catalyst oxygen sensor is provided. The system generally includes a fuel control module that commands fuel to transition from a rich condition to a lean condition and that commands fuel to transition from the lean condition to the rich condition. A first diagnostic module monitors the post-catalyst oxygen sensor during the transition from the rich condition to the lean condition. A second diagnostic module monitors the catalyst during the transition from the lean condition to the rich condition.

Abstract: An improved control for the heater element of a motor vehicle engine exhaust gas oxygen sensor determines the temperature of the heater element and adjusts the heater element current by closed-loop control to minimize deviation of the heater element temperature from a desired heater temperature determined in relation to the desired oxygen sensor temperature. The heater temperature is calculated based on the heater element resistance, and the heater resistance is adaptively adjusted to account for sensor-to-sensor variation. The adaptive adjustment is updated based on a deviation of the measured heater element resistance from an expected value under predetermined calibration conditions at engine start-up.

Abstract: An improved control for the heater element of a motor vehicle engine exhaust gas oxygen sensor determines the temperature of the heater element and adjusts the heater element current by closed-loop control to minimize deviation of the heater element temperature from a desired heater temperature determined in relation to the desired oxygen sensor temperature. The heater temperature is calculated based on the heater element resistance, and the heater resistance is adaptively adjusted to account for sensor-to-sensor variation. The adaptive adjustment is updated based on a deviation of the measured heater element resistance from an expected value under predetermined calibration conditions at engine start-up.