| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an air-fuel ratio control device capable of promptly detecting activity of a downstream side air-fuel ratio detecting means while preventing a harmful component from being discharged into atmosphere. <P>SOLUTION: The air-fuel ratio control device is provided with an emission control catalyst 21, an upstream side air-fuel ratio detecting means 26, the downstream side air-fuel ratio detecting means 27, and an activity determination means determining if the downstream side air-fuel ratio detecting means is in an active state or not and sets a fuel injection amount so that an air-fuel ratio detected by the upstream side air-fuel ratio detecting means matches a target air-fuel ratio. The air-fuel ratio control device is further provided with a catalyst temperature detecting means detecting the temperature of the emission control catalyst, and sets the target air-fuel ratio based on the temperature of the emission control catalyst detected by the catalyst temperature detecting means when the activity determination means determines that the downstream side air-fuel ratio detecting means is in a non-active state. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
