Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains
unchanged, ready to repeat the process.
This device sometimes requires the use of heat shields, due to its high operating temperatures. The heat shields are necessary to protect chassis
components, passenger compartment and other areas from heat related damage.
General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs are: single bed
monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three way
(reduction) catalyst.
The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The
three way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide
and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three way catalysts.
A small diameter fuel tank filler tube is used on catalytic converter equipped vehicles to prevent the larger service station pump nozzle, used for
leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalyst, rendering them ineffective, the use of
unleaded fuels is mandatory in catalytic converter equipped vehicles.
