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:
Oct. 25, 1994
Filed:
Dec. 16, 1993
Wallace R Wade, Farmington Hills, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
Monitoring a catalyst positioned downstream of a Y-shaped exhaust path includes positioning an exhaust gas oxygen sensor just upstream and just downstream of the catalyst and using the two sensors together to monitor catalyst activity. Such monitoring is discontinued when the exhaust gas oxygen sensor switching rate of the upstream exhaust gas oxygen sensor is below a minimum threshold value. The upstream exhaust gas oxygen sensor does not provide an air fuel ratio feedback signal but instead, such a signal is provided by two additional exhaust gas oxygen sensors, one sensor being positioned in each of the two legs of the Y exhaust path coming from the engine.