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:
Aug. 04, 1992
Filed:
Mar. 29, 1991
Takashi Ogawa, Toyota, JP;
Kazuhiko Funato, Toyota, JP;
Abstract
In a double air-fuel ratio sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, the actual air fuel ratio is adjusted in accordance with the air-fuel ratio correction amount calculated by using the output of the upstream-side air-fuel ratio sensor and the output of the downstream-side air-fuel ratio sensor. In this system, a detection whether or not the catalyst converter is deteriorated is carried out by using the output of the downstream-side air-fuel ratio sensor when the feedback control condition is satisfied. This detecting operation is prohibited when the upstream-side air-fuel ratio sensor is in an abnormal state.