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:
May. 16, 1995

Filed:

Feb. 01, 1994
Applicant:
Inventors:

Shigetaka Kuroda, Wako, JP;

Yoichi Iwata, Wako, JP;

Hidekazu Kano, Wako, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
36443105 ; 60274 ; 60276 ; 60285 ; 36443101 ; 36443104 ; 36443103 ;
Abstract

A method of detecting deterioration of a three-way catalyst of an internal combustion engine comprises the steps of (1) obtaining a first signal and a second signal based on respective signals outputted from a pre-catalyst O.sub.2 sensor and a post-catalyst O.sub.2 sensor at least one of when the fuel supply to the engine is increased and when the fuel supply to the engine is interrupted, (2) comparing a waveform of a signal outputted from the pre-catalyst O.sub.2 sensor with a waveform of a signal outputted from the post-catalyst O.sub.2 sensor, based on the first and second signals while the engine is in a predetermined stable operating condition, and (3) determining from results of the comparison whether or not the three-way catalyst is deteriorated.


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