| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a deterioration diagnosing device for an oxygen concentration sensor which accurately diagnoses deterioration in regard to the oxygen concentration sensor provided in an exhaust system of a diesel engine. <P>SOLUTION: In an electronic controller 90 carrying out overall control of an operating state of a diesel engine 1, fuel (a reducing agent) of a predetermined quantity is added to an oxygen concentration sensor 73 upstream side of the exhaust system 40 through a fuel adding valve during an idling period of the engine 1, and a deterioration degree of the oxygen concentration sensor 73 is diagnosed on the basis of responsiveness of a sensor output with respect to adding of the fuel. <P>COPYRIGHT: (C)2004,JPO |
