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:
Mar. 27, 2001
Filed:
Feb. 19, 1999
Kaoru Otsuka, Nishikamo-gun, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
An air-fuel ratio control system for a multi-cylinder internal combustion engine is equipped with an exhaust emission control catalyst disposed in an exhaust passage of the engine, air-fuel ratio control means for controlling an air-fuel ratio of at least one of the plurality of cylinders, and an exhaust gas temperature sensor operating as catalyst temperature detection. During a cold start of the engine, the air-fuel ratio control means achieves one of rich-state and stoichiometric operation in all of the cylinders until the temperature of the exhaust emission control catalyst reaches a predetermined temperature. After the temperature of the exhaust emission control catalyst has reached the predetermined temperature, the air-fuel ratio control means starts lean-state operation in a first portion of the plurality of cylinders while maintaining rich-state operation in a second portion of the plurality of cylinders.