Computer Controlled Catalytic Converter: Description
NOTE:
This article contains information which is applicable to 1979 models and to 1980 Buick Skylark, Chevrolet Citation, Oldsmobile Omega and Pontiac Phoenix.
The Computer Controlled Catalytic Converter (C-4) system closely controls air/fuel ratio through a feedback system from an oxygen sensor in the exhaust system. The major components of this system include an exhaust gas oxygen sensor, an Electronic Control Module (ECM), an electronically controlled carburetor, and a 3-way catalytic converter. See Figure.
This system is used on some 1979 models with 231" (3.8L - VIN 2) V6 engines for sale in California, and also on 1980 Buick Skylark, Chevrolet Citation, Oldsmobile Omega and Pontiac Phoenix models equipped with 151" (2.5L) 4-cylinder engine or 171" (2.8L) V6 engine. All models are so equipped if sold in California.
NOTE:
A similar system is also used in 1979, except it is vacuum controlled. See GENERAL MOTORS ELECTRONIC FUEL CONTROL SYSTEM in this section. This system is applicable to Chevrolet Monza, Oldsmobile Starfire and Pontiac Phoenix and Sunbird. These models are equipped for California only.