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:
Jun. 09, 1998
Filed:
Dec. 06, 1996
Ulrich Staufenberg, Diethardt, DE;
Peter Olejnik, Bad Soden, DE;
VDO Adolf Schindling AG, Frankfurt, DE;
Abstract
A method of checking the efficiency of a catalytic converter in an internal combustion engine in which a ratio is formed from the amplitude of the output signal of a lambda probe arranged behind the catalytic converter and from the amplitude of the output signal of a lambda probe arranged in front of the catalytic converter. The ratio is compared with a threshold value, the catalytic converter being recognized as deficient if the ratio is less than the threshold value. In order to compensate for the lack of sharpness resulting from the manufacturing process and the aging of the probe, the method provides for determining the efficiency of the catalyst in which an extreme value of the corresponding probe output signal is determined for each probe after each probe reversal.