| 摘要 |
<p>PURPOSE:To provide a purifying ratio detector for catalyst by which the purifying ratio of the catalyst can be detected even when the purifying ratio of the catalyst is lowered. CONSTITUTION:A downstream sensor 10 downstream of catalytic converter rhodium 3 is formed by using a titania oxygen sensor, and since an Rh adding quantity to a titania layer and an over coat layer is increased or a pore diameter of an over coat is set small, when oxygen concentration in exhaust gas is changed from a rich condition to a lean condition or from the lean condition to the rich condition, speed of response of output voltage can be set slow. Thereby, even if the purifying ratio of the catalytic converter rhodium 3 is lowered and the air-fuel ratio is changed, an output change of the downstream sensor 10 cannot follow a change in the air-fuel ratio speedily, so that the output change is caused according to change width of the air-fuel ratio.</p> |
