To eliminate HC or others adsorbed to an adsorber provided at the upstream side of a catalyst without lowering driveability and increasing costs.
During starting an engine 1, exhaust gas is passed through a honeycomb 5 in an adsorber 4, provided in part of the large-diameter portion 41 of an exhaust pipe 3 at the upstream side of a catalytic converter rhodium 10, with an exhaust gas flow passage switch valve 6 switched by an ECU 11 to adsorb harmful HC or others to adsorbent carried on the honeycomb 5. When warm-up operation is completed and the rhodium 10 is activated, the switch valve 6 opens a flow passage 43 but HC and others adsorbed to the adsorber 4 is treated by the catalyst 10 by switching the switch valve 6 again during decelerating operation to carry exhaust gas to the honeycomb 5 for elimination. In this case, a fuel injection amount is reduced corresponding to an elimination amount.
TANAKA MASAICHI
SAKAI TATSUO
ITO TAKAAKI
TANAKA HIROSHI
TOYOTA MOTOR CORP
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