| 摘要 |
<P>PROBLEM TO BE SOLVED: To inhibit wasteful fuel consumption in execution of fuel addition control aiming at inhibition of clogging while accurately inhibiting an addition valve from clogging. <P>SOLUTION: Temperature raise control raising catalyst bed temperature to target bed temperature is executed through fuel addition from the addition valve 46. A correction value K used for correction of fuel addition quantity is calculated to be a value corresponding to slippage between catalyst bed temperature and target bed temperature and is stored in RAM during the control. When it is determined the clogging occurs in the addition valve 46, fuel adding control of the addition valve 46 aiming at inhibition of clogging of the addition valve 46 is executed. Such fuel addition control is strongly executed as the correction value K stored in the RAM is larger, and is weakly executed as the correction value K is smaller. <P>COPYRIGHT: (C)2008,JPO&INPIT |
