GM Full Size Vans 1967-1986 Repair Guide

Oxidizing Catalytic Converter



See Figure 1

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Fig. Fig. 1: The catalytic convertor is mounted forward of the muffler

An underfloor oxidizing catalytic converter is used to control hydrocarbon and carbon monoxide emissions on many 1975 and later models. Control is accomplished by placing a catalyst in the exhaust system to enable all exhaust gas flow to pass through it and undergo a chemical reaction before passing into the atmosphere. The chemical reaction involved is the oxidizing of hydrocarbons and carbon monoxide into water vapor and carbon dioxide.