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:
Jan. 16, 1996
Filed:
Apr. 11, 1994
Honda Giken Kogyo K.K., Tokyo, JP;
Abstract
An oxygen sensor deterioration-detecting system for an internal combustion engine having a plurality of groups of cylinders groups, an exhaust system having a plurality of exhaust passages extending, respectively, from the cylinder groups, and catalytic converters arranged in the exhaust system, and a plurality of upstream oxygen sensors arranged, respectively, in the exhaust passages at locations upstream of the catalytic converters, includes a single downstream oxygen sensor arranged in a confluent portion of the exhaust passages at a location downstream of the catalytic converters, for detecting the mixed air-fuel ratio of exhaust gases emitted from the cylinder groups. An ECU is responsive to outputs from the upstream oxygen sensors and an output from the downstream oxygen sensor, for determining air-fuel ratio control amounts for respective ones of the cylinder groups, and for controlling the air-fuel ratios of air-fuel mixtures supplied into the respective cylinder groups by the use of the air-fuel ratio control amounts determined. The ECU detects deterioration of each upstream oxygen sensor, based on an output from the upstream oxygen sensor obtained by the air-fuel ratio control based on a corresponding one of the air-fuel ratio control amounts.