Abstract: A method for sensing an air-fuel ratio of exhaust gasses from an engine of a vehicle using a sensor is provided. The method may comprise pumping a current in a pumping cell during; reducing said pumping during a set of operating conditions; and adjusting a fuel injection amount or an air amount into the engine to maintain a desired air-fuel ratio based on the sensor. In this way, a reference voltage can be driven by chemical reactions to equilibrate and provide an accurate indication of stoichiometry, similar to a HEGO sensor. Likewise, outside of stoichiometry, the reference voltage is controlled in a one-sided fashion via positive and negative pumping current at respective voltage limits to provide an indication of air-fuel ratio over a wide range.

Abstract: A method for sensing an air-fuel ratio of exhaust gasses from an engine of a vehicle using a sensor, the sensor having a pumping cell and a reference cell, the method comprising pumping a current in the pumping cell during at least a first set of operating conditions; reducing said pumping during at least a second set of operating conditions; providing a signal from the sensor during at least the first and second sets of operating conditions; and adjusting at least one of a fuel injection amount and an air amount into the engine to maintain a desired air-fuel ratio based on the signal during at least the first and second sets of operating conditions.

Abstract: An oxygen sensor for measuring exhaust gases of an internal combustion engine is described. The sensor provides an output that has a high gain near the stoichiometric air-fuel ratio, and a lower gain in the lean and rich air-fuel ratio regions. Further, the sensor provides wide range air-fuel ratio signal to be used in engine feedback control.

Abstract: An oxygen sensor for measuring exhaust gases of an internal combustion engine is described. The sensor provides an output that has a high gain near the stoichiometric air-fuel ratio, and a lower gain in the lean and rich air-fuel ratio regions. Further, the sensor provides wide range air-fuel ratio signal to be used in engine feedback control.