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.

Date of Patent:
Nov. 03, 1992

Filed:

Aug. 26, 1991
Applicant:
Inventors:

Peter J Grutter, Livonia, MI (US);

Gerald G Stock, Whitmore Lake, MI (US);

John A Cushing, Taylor, MI (US);

Alexander Y Gopp, Ann Arbor, MI (US);

Assignee:

Ford Motor Company, Dearborn, MI (US);

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
F01N / ;
U.S. Cl.
CPC ...
60274 ; 60276 ; 60277 ; 60285 ; 123691 ;
Abstract

An exhaust gas oxygen sensor downstream of a catalytic converter is used to control a closed loop air/fuel ratio control system. A measured limit cycle frequency at various engine speed/load conditions is compared to stored benchmark limit cycle frequencies as functions of engine speed/load conditions. If the measured frequency is higher, the catalytic converter is considered to be degraded.


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