Methods and systems are provided for adjusting engine operating parameters in response to an emission output from vehicles within a region. In one example, a method comprises adjusting engine operating parameters in a portion of the vehicles to decrease an emission output therefrom.

An electrically-operated actuator rotates a valve toward its closing side or opening side. A valve urging part urges the valve from a fully-closed position toward the opening side. An ACT control part controls the electrically-operated actuator to drive. A set load of the valve urging part is smaller than a set load that is capable of returning the valve from a fully-closed position to an intermediate position only by urging force of the valve urging part. When a position of the valve at time of turning off an IG switch for stopping operation of an internal-combustion engine is on the closing side of the intermediate position, the ACT control part shifts the valve to the intermediate position by the electrically-operated actuator after the IG switch is turned off.

Some embodiments of the teachings herein include methods for operating an exhaust gas sensor with a pump electrode, a measuring electrode, and a reference electrode. An example includes: discharging oxygen from the measuring cavity by applying a measurement current to the measuring electrode so a measurement voltage between the measuring electrode and the reference electrode is kept at a predetermined first setpoint value; discharging oxygen from the pump cavity by applying a pump current to the pump electrode so an electrode voltage between the pump electrode and the reference electrode is kept at a predetermined second setpoint value; determining a nitrogen oxide value based at least in part on a value of the measurement current; adapting the first setpoint value for the measurement voltage based on the determined nitrogen oxide value; and/or adapting the second setpoint value for the electrode voltage based on the determined nitrogen oxide value.

A method for recognizing the type of fuel actually used in an internal combustion engine; the recognition method includes the steps of: sensing the intensity of the vibrations generated by the internal combustion engine within a measurement time window; determining the value of at least one synthetic index by processing the intensity of the vibrations generated by the internal combustion engine within the measurement time window; comparing the synthetic index with at least one predetermined comparison quantity; and recognizing the type of fuel actually used as a function of the comparison of the synthetic index to the comparison quantity; and forcedly altering, when detecting the intensity of the vibrations, the engine control with respect to the normal standard engine control, so as to enhance the behavioral differences of the different types of fuel that can be used by the internal combustion engine.

The objective of the present invention is to provide an exhaust purification system that is capable of purifying exhaust gas during both lean and stoichiometric driving. The exhaust purification system is equipped with: a feedback-use identifier, which identifies parameter values such that the error between the output value from a LAF sensor and the estimated value for the LAF sensor output as obtained from a model equation is minimized; and a stoichiometric driving mode controller. The controller performs feedback control and thereby determines the fuel injection amount such that in the stoichiometric driving mode the equivalence ratio value as calculated from the parameters reaches a target value which is set such that a three-way purification reaction occurs in an under-engine catalyst. The identifier identifies the model parameters before feedback control is initiated by the controller.

Some embodiments of the teachings herein include methods for operating an exhaust gas sensor with a pump electrode, a measuring electrode, and a reference electrode. An example includes: discharging oxygen from the measuring cavity by applying a measurement current to the measuring electrode so a measurement voltage between the measuring electrode and the reference electrode is kept at a predetermined first setpoint value; discharging oxygen from the pump cavity by applying a pump current to the pump electrode so an electrode voltage between the pump electrode and the reference electrode is kept at a predetermined second setpoint value; determining a nitrogen oxide value based at least in part on a value of the measurement current; adapting the first setpoint value for the measurement voltage based on the determined nitrogen oxide value; and/or adapting the second setpoint value for the electrode voltage based on the determined nitrogen oxide value.