| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an apparatus for detecting troubles of an exhaust secondary air supply device, for simply and accurately detecting a trouble of the exhaust secondary air supply device. <P>SOLUTION: In a V shape engine having air supply pipes connected to respective banks, two air-fuel ratio sensors are provided at the positions located on downstream side of the air supply pipes so as to generate the output according to the concentration of oxygen in the exhaust gas. The difference Δmax between the maximum value KO2RMAX and the maximum value KO2LMAX of the air-fuel ratio feedback correction is calculated based on the output from the air-fuel ratio sensors (S16, S18), and then the calculated difference is compared with a specified value (S20). When the calculated difference exceeds the specified value, it is detected (S24) that the exhaust secondary air supply device is out of order. <P>COPYRIGHT: (C)2008,JPO&INPIT |
