Abnormality diagnosing apparatus of exhaust gas sensor

An abnormality diagnosing apparatus of an exhaust gas sensor comprising:

• a downstream exhaust gas sensor installed on a downstream side of a catalyst in an exhaust gas path of an internal combustion engine;
• and
• sensor abnormality diagnosing means for diagnosing presence or absence of an abnormality of the downstream exhaust gas sensor based on an output of the downstream gas sensor,
• wherein the sensor abnormality diagnosing means executes an abnormality diagnosis of the downstream gas sensor based on the output of the downstream gas sensor in an operating region exceeding a cleaning function of the catalyst.

An abnormality diagnosing apparatus of an exhaust gas sensor comprising:

• a downstream gas sensor installed on a downstream side of a catalyst for cleaning an exhaust gas of an internal combustion engine;
• abnormality diagnosing means for diagnosing presence or absence of an abnormality of the downstream gas sensor based on an output of the downstream gas sensor;
• and
• diagnosing gas introducing means for introducing an abnormality diagnosing gas to an upstream side of the downstream gas sensor in an exhaust path at the downstream side of the catalyst,
• wherein the abnormality diagnosing means executes an abnormality diagnosis of the downstream gas sensor by introducing the abnormality diagnosing gas to the upstream side of the downstream gas sensor by the diagnosing gas introducing means.

An abnormality detecting apparatus of an exhaust gas sensor comprising:

• a catalyst arranged in an exhaust path of an internal combustion engine for cleaning exhaust gas of the internal combustion engine;
• an exhaust gas sensor arranged downstream the catalyst for detecting an oxygen concentration of the exhaust gas from the catalyst;
• correction amount setting means for setting a correction amount of correcting an air/fuel ratio of mixture of the internal combustion engine based on a detected value of the exhaust gas sensor for each operating condition of the internal combustion engine;
• storing means for storing the correction amount set by the correction amount setting means;
• and
• abnormality detecting means for detecting an abnormality of the exhaust gas sensor based on the correction amount stored in the storing means.