| 摘要 |
An abnormal diagnosis device capable of specifying abnormality of an ammonia slip catalyst provided on a downstream side of a selection reduction catalyst, and an exhaust gas purification device of an internal combustion engine including the abnormal diagnosis device are provided. A purification rate diagnosis unit which diagnoses an NO x purification rate in the exhaust gas purification device, and an abnormality determination unit which specifies abnormality of the ammonia slip catalyst based on a diagnostic result of the NO x purification rate obtained at the time of a high load operation of the internal combustion engine and a diagnostic result of the NO x purification rate obtained at the time of a low load operation of the internal combustion engine are provided. |
