| 摘要 |
<P>PROBLEM TO BE SOLVED: To inhibit deactivation of a catalyst due to inflow of low temperature exhaust gas with accompanying restart of an engine while considering emission control capacity after restart in an engine provided with NOx trap catalyst. <P>SOLUTION: The NOx trap catalyst is forcibly heated and air fuel ratio of exhaust gas in the forcible heating is adjusted to air fuel ratio according to quantity of NOx trapped by the NOx trap catalyst (S403-405) during restart detection. If NOx trap quantity has reached limit trap quantity (=NOX1) of the catalyst, air fuel ratio of exhaust gas is adjusted to theoretical value or value less than that (=λs). <P>COPYRIGHT: (C)2007,JPO&INPIT |
