Century L4-2.2L VIN 4 (1994)
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.
CONSTRUCTION:
General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs are:
1.
Single bed monolith
2.
Dual bed monolith
3.
Single bed pellet
4.
Dual bed pellet
The two types of catalysts used are an Oxidation catalyst and a Three-Way (Oxidation/Reduction) catalyst. The Oxidation catalyst is coated with a
material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The Three-Way (Oxidation/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 neck is used on catalytic converter equipped vehicles to prevent the use of leaded fuel pump nozzles. Since the
use of leaded fuels, or fuel additives containing lead, contaminates the catalysts, rendering the catalyst ineffective, the use of unleaded fuels is
mandatory on catalytic converter equipped vehicles.
