| 摘要 |
<p>PURPOSE:To decide the deterioration condition of a catalytic body by means of the only exhaust sensor, by making comparison of exhaust sensor detection signals which are in a state in which the 1st bypass passage and the 2nd bypass passage are respectively connected in changeover to an assembly bypass passage by means of a changeover valve. CONSTITUTION:A control portion 44, under a predetermined operation condition, conducts comparison between an O2 sensor 30 detection signal, due to the exhaust of the 1st bypass passage 16 which is in a state in which the 1st bypass passage 16 is connected in changeover to an assembly bypass passage 24 by means of a changeover valve 28, and an O2 sensor 30 detection signal which is in a state in which the 2nd bypass passage 20 is connected in changeover to the assembly bypass passage 24, and determines the deterioration condition of a catalytic body 12. As a result, the deterioration condition of the cleaning function of the catalytic body can be decided by means of the only exhaust sensor.</p> |
