| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress worsening of emission and drivability to the minimum extent and determine degree of deterioration of exhaust gas purifying catalyst precisely. <P>SOLUTION: This catalyst deterioration determining device is provided with the catalyst 32 purifying exhaust gas, a first air-fuel ratio sensor 35 arranged on the upstream side of the catalyst 32, a second air-fuel ratio sensor 36 arranged on the downstream side of the catalyst 32, a means for switching air-fuel ratio between lean air-fuel ratio and rich air-fuel ratio by active A/F control based on output of the second air-fuel ratio sensor 36 and calculating amount of oxygen occlusion of the catalyst 32 per change-over of air-fuel ratio based on output of the first air-fuel ratio sensor 35, and a means for determining degree of deterioration of the catalyst 32 based on an amount of oxygen occlusion and the number of calculation of the amount of oxygen occlusion. <P>COPYRIGHT: (C)2004,JPO</p> |
