Patent ID: 7286926
Filing Date: 2007-10-23
Classification: F01N,F02D,Y02T

Abstract:
1. A deterioration detecting apparatus for an exhaust gas sensor of an internal combustion engine, the exhaust gas sensor including a sensor element and a heater that heats the sensor element, the deterioration detecting apparatus comprising: a first parameter computing means for computing a first sensor characteristic parameter, which is related to a characteristic of the sensor element, by estimating an interchange state of thermal energy between the sensor element and a periphery of the sensor element; an element impedance sensing means for sensing impedance of the sensor element; a second parameter computing means for computing a second sensor characteristic parameter, which is related to the characteristic of the sensor element, based on the impedance sensed by the element impedance sensing means; and a sensor deterioration determining means for determining a degree of deterioration of the exhaust gas sensor by comparing the first sensor characteristic parameter and the second sensor characteristic parameter.