A gas sensor processing apparatus (1) which includes voltage shift means (11, 19, S1071) for shifting a detection element voltage (VE) produced between electrodes (3P, 3N) of a detection element (3) from a pre-shift voltage (VE1) to a post-shift voltage (V...

An air fuel ratio control system includes an exhaust gas sensor to sense an oxygen concentration in an exhaust passage of an internal combustion engine, and a controller. The controller is configured to judge that the exhaust gas sensor is in an active sta...