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:
Oct. 11, 1994
Filed:
Nov. 26, 1993
Glenn A Zimlich, Dearborn Heights, MI (US);
Daniel V Orzel, Westland, MI (US);
Tri T Truong, Inkster, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A control system and method maintains engine air/fuel operation near stoichiometry in response to exhaust gas oxygen sensors positioned both upstream and downstream of a catalytic converter. A converter efficiency test cycle is generated during air/fuel feedback control after engine operation occurs in a plurality of airflow ranges for a period determined by a count in transitions of a feedback variable derived from the upstream sensor. Upon each transition in the downstream sensor, the measurement of inducted airflow at which such transition occurred is accumulated. At the end of the test cycle, converter efficiency is determined by an average of such airflow accumulations.