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:
Aug. 04, 1998

Filed:

Aug. 30, 1996
Applicant:
Inventor:

Thomas Roger Thoreson, Brighton, MI (US);

Assignee:

General Motors Corporation, Detroit, MI (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01N / ;
U.S. Cl.
CPC ...
60274 ; 60276 ; 60277 ; 60284 ; 731181 ;
Abstract

A procedure has been proposed for diagnosing operability of a catalytic treatment device for catalytically treating internal combustion engine exhaust gas, by determining whether the catalytic treatment device reaches a light-off operating condition within a short period of time following an engine coldstart operation. When catalytic converter temperature reaches a temperature level associated, for an operable catalytic converter, with light-off, the operating efficiency of the converter is sampled and, if persistently below an acceptable operating efficiency over a number of coldstart operations, a deterioration in the converter is stored and indicated.


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