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:
Nov. 30, 1993
Filed:
Aug. 27, 1992
Douglas R Hamburg, Bloomfield Hills, MI (US);
Kelvin L Dobbins, Dearborn, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
Apparatus, method and system are provided for monitoring catalytic converter efficiency in treating exhaust gas from an internal combustion engine. The air/fuel ratio fed to the engine is perturbed on a cylinder-to-cylinder basis above and below a mean or average air/fuel ratio. The signal from an exhaust gas exposed to the exhaust gas sensor downstream of the converter for the perturbation interval is compared to the signal for a non-perturbation interval. A signal is generated when the comparison indicates catalytic converter efficiency below a minimum acceptable level. The comparison may be carried out by comparing the difference in the mean value of the EGO sensor output signal for the perturbation and non-perturbation intervals to a preselected and stored reference value corresponding to the minimum acceptable efficiency. The efficiency monitoring test system may be incorporated into fuel control means for controlling air/fuel ratio during normal engine operation.