| 摘要 |
PROBLEM TO BE SOLVED: To effectively suppress catalyst exhaust gas odor and to surely prevent a speed reduction type defect at the time of speed reduction even in the case that an open failure occurred at a purge control valve. SOLUTION: In the case that fuel increase history is updated during a speed reduction fuel cut-off operation, opening of a throttle valve 18 is made larger than idle opening and larger quantity of air than normal speed reduction time is distributed to an exhaust gas passage and catalyst is made to be in oxidation state. However, in the case that the open failure of the purge control valve is detected, to surely avoid occurrence of speed reduction type defect owing to decrease of negative torque or generation of positive torque caused by combustion of purge gas, increase of opening of the throttle valve 18 during the speed reduction fuel cut-off operation is inhibited. COPYRIGHT: (C)2007,JPO&INPIT
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