摘要 |
<p>An apparatus for diagnosing deterioration of a catalyst for an internal combustion engine, having a first catalyst (223) and a second catalyst (224) and provided with sensors (226, 227) for detecting a particular exhaust component before and after the first catalyst (223), wherein a relationship between a deterioration property involved in clarification of an exhaust gas of the internal combustion engine by a combination of the first catalyst (223) and the second catalyst (224) and a deterioration property of the first catalyst 223 are determined previously; a deterioration degree of the first catalyst (223) is calculated according to outputs from the sensors (226, 227) disposed before and after the first catalyst (223); deterioration of the first catalyst (223) is judged according to the deterioration degree; and deterioration of the second catalyst (224) is judged according to the deterioration degree of the first catalyst (223).</p> |