| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a catalyst deterioration determination device which can properly distinguish and determine uniform deterioration or partial deterioration of an SCR catalyst. <P>SOLUTION: The catalyst deterioration determination device determines deterioration of the SCR for carrying out exhaust emission control using a reducing agent added in an exhaust passage. In a deterioration determination means, a control is carried out in which the reducing agent is added in the exhaust passage so that an equivalent ratio between NOx and NH<SB POS="POST">3</SB>flowing into the SCR catalyst is changed, and the SCR catalyst is determined to be in either states of the uniform deterioration or the partial deterioration, on the basis of conversion efficiency by the SCR catalyst which is obtained upon the control. Thus, the uniform deterioration and the partial deterioration of the SCR catalyst can be properly distinguished and determined. <P>COPYRIGHT: (C)2013,JPO&INPIT |
