EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To appropriately set a target oxygen storage quantity of a catalyst having an oxygen storage ability. SOLUTION: An A/F sensor 15 and an O2sensor 16 are respectively provided on the upstream/downstream sides of the catalyst 13 arranged in an exhaust passage 12. The maximum oxygen storage quantity is corrected in response to the time passing after the exhaust on the upstream side of the catalyst 13 is leaned till a determination that exhaust characteristic on the downstream side of the catalyst 13 is lean is done and the time passing after the exhaust on the upstream side of the catalyst 13 is leaned till a computing value of the oxygen storage quantity becomes the set maximum oxygen storage quantity, and a target oxygen storage quantity is set on the basis of the corrected maximum oxygen storage quantity. COPYRIGHT: (C)2004,JPO