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. 22, 2002
Filed:
Jan. 20, 2000
Michael John Cullen, Northville, MI (US);
Brent Edward Sealy, Dearborn, MI (US);
Kenneth John Behr, Farmington Hills, MI (US);
Richard Andrew Booth, Canton, MI (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
A method and system for diagnosing catalyst operation in an internal combustion engine having a two-bank, three EGO sensor structure includes monitoring when the EGO sensors switch states between rich and lean and determining the ratio between a switch count of the post-catalyst EGO sensor signal and a switch count of a pre-catalyst EGO sensor signal over a selected time period. If the exhaust bank is a one-sensor bank having only a post-catalyst EGO sensor and not a pre-catalyst EGO sensor, the system uses the switch count from the pre-catalyst EGO sensor in the two-sensor bank to calculate the switch ratio, thereby allowing calculation of two switch ratios without two matched pairs of EGO sensors. The switch ratio indicates the efficiency of the catalyst and may be compared with later-generated ratios to monitor converter efficiency over time.