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:
Jan. 26, 1999

Filed:

Jul. 31, 1997
Applicant:
Inventors:

Hong Zhang, Regensburg, DE;

Alexander Ketterer, Regensburg, DE;

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

The catalytic converter of an internal combustion engine is monitored with regard to its conversion capacity. A sensor downstream of the catalytic converter measures the oxygen concentration in the exhaust gas leaving the catalytic converter. A mean value is determined of the oxygen concentration measurement signal, and the area between the measurement signal and the mean value is calculated. The area is then compared with a predetermined comparison value, and a low conversion capacity of the catalytic converter is deduced from the comparison if the area is greater than the comparison value. A corresponding error signal may be stored in memory or immediately output as a warning for the driver of the vehicle.


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