| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a diagnostic device for diagnosing a catalyst or air-fuel ration correctly even when a misfire or a trouble in a secondary air system occurs. SOLUTION: Misfire or a trouble in the secondary air system is detected by misfire detecting means 9 or a secondary air system trouble detecting means 10. A correction means 13 corrects a deterioration index calculated by a deterioration index calculating means 11 according to the result of the detection. A deterioration determining means 12 determines using the value after correction. If the condition of the misfire, etc., is severe, a suspending means 14 suspends the determination of the deterioration judging means.</p> |
