The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 03, 2007
Filed:
Jul. 15, 2002
Takahiro Uchida, Susono, JP;
Hiroshi Sawada, Gotenba, JP;
Toshinari Nagai, Sunto-gun, JP;
Akihiro Katayama, Toyota, JP;
Yasuhiro Kuze, Susono, JP;
Naoto Kato, Susono, JP;
Takahiro Uchida, Susono, JP;
Hiroshi Sawada, Gotenba, JP;
Toshinari Nagai, Sunto-gun, JP;
Akihiro Katayama, Toyota, JP;
Yasuhiro Kuze, Susono, JP;
Naoto Kato, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
An upstream side catalyst and a downstream side catalyst are disposed in an exhaust passage. A first oxygen sensor is disposed between these two catalysts and a second oxygen sensor is disposed downstream of the downstream side catalyst. The air-fuel ratio is forcibly oscillated and the oxygen storage capacity of the upstream side catalyst is detected. Deterioration of the upstream side catalyst is then detected based on whether this oxygen storage capacity is larger than a predetermined value. The forced oscillation of the air-fuel ratio is performed only when the oxygen storage state of the downstream side catalyst is appropriate.