Description & Operation: Notes

The catalytic converter(s) is installed in the exhaust system in front of the muffler so that all exhaust gas must pass through the converter(s). The converter is a device that reduces exhaust emissions. There are 2 types of catalytic converters, oxidation and 3-way converters. The oxidation converter contains material coated with platinum and palladium. This catalyst reduces Hydrocarbons (HC) and Carbon Monoxide (CO) emissions. The three-way converters contain material coated with platinum, palladium and Rhodium. This catalyst reduces HC, CO, and Oxides of Nitrogen (NOx).

The material inside the converter is one of two types; coated one piece honeycombed block that is non-serviceable, or small beads of material that are coated with catalyst and are serviceable. Catalytic converters normally operate at 1300-1600°F. If an overrich mixture enters the converter, the temperature can go much higher. A converter that is subjected to raw fuel or a misfiring cylinder can get hot enough to glow Red. If the problem is not caught early and corrected, it may melt the converter. If replacing a damaged converter, always correct the cause first.

Fig 1: Cutaway of Oxidation Catalytic Converter

Courtesy of CHRYSLER GROUP, LLC

NOTE: Use unleaded fuel only on vehicles using catalytic converters. If leaded fuel is used, the Tetra Eythel Lead will coat the palladium, platinum and Rhodium, rendering these catalyst inoperative. If this happens, the converter must be replaced.