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:
Sep. 23, 2003
Filed:
Jul. 18, 2002
Hideaki Kobayashi, Yokohama, JP;
Shigeaki Kakizaki, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A catalyst which has an oxygen storage function is provided in the exhaust gas pipe of an engine The oxygen storage amount is estimated based on the output of the air/fuel ratio sensor upstream of the catalyst The air/fuel ratio is controlled so that the oxygen storage amount coincides with the target value. When the output of the downstream air/fuel ratio sensor continuously displays a rich or a lean value for more than a determination time which is varied continuously with respect to operating conditions, deterioration in the upstream air/fuel ratio sensor is detected. Thus the output of the upstream air/fuel ratio sensor is corrected based on the output of the downstream air/fuel ratio sensor In this manner, output fluctuations are corrected based on the deterioration of the air/fuel ratio sensor upstream of the catalyst.