Catalytic Converter: Description and Operation

Catalyst Operation.:

CAUTION: Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury.

NOTE: When jacking or lifting vehicle from frame side rails, be certain lift pads do not contact catalytic converter otherwise damage to converter may result.


SYSTEM DESCRIPTION
The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, exiting the tailpipe.

The converter allows for 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.


CATALYST CONSTRUCTION
The catalyst coating on the three-way (reduction) catalyst contains platinum and rhodium which lowers the levels of oxides of nitrogen (NOx) as well as hydrocarbons (HC) and carbon monoxide (CO).

Saturn uses Single or Dual bed monolith converter.

Periodic maintenance of the exhaust system is not required. If the vehicle is raised for other service, it is advisable to check the condition of the complete exhaust system.


FUEL PIPE RESTRICTOR
A small diameter fuel tank filler neck is used on catalytic converter equipped vehicles to prevent the use of leaded fuel pump nozzles.


WARNING: Since the use of leaded fuels, or fuel additives containing lead, contaminates (damages) the catalysts, the use of unleaded fuels is mandatory on catalytic converter equipped vehicles.