This article has information about how an automotive catalytic converter works.
Experiments determined that passing exhaust gases over a catalyst will cause
the pollutants in the exhaust to be completely burned and result in water (H2O)
and carbon dioxide (CO2) byproduct. The catalytic converter was developed in the
early 1970's when severe air pollution was prevalent, and was made mandatory in
auto mobile manufacturing in the US in 1976. The catalytic converter or "cat" is
an emission control device designed to remove un-burnt fuel in the exhaust system.
This un-burnt fuel is a major component in air pollution. The name catalytic
converter was derived from its operation, utilizing a catalyst combined with heat
to convert the un-burned gases into burned gases. The catalyst is heated to excite
the chemical catalyst, this burns the un-burned fuel making the catalyst even hotter
furthering the effect (thermo reaction.) A catalytic converter starts with a ceramic
honeycomb about 3 inches by 5 inches by 8 inches which can vary. This honeycomb
is coated with a thin layer of catalyst material and is placed inside a metal container
with an inlet and outlet connection. The honeycomb design provides maximum exposure
to the exhaust gases.
Catalytic Converter Location
Catalytic converter locations can vary depending on manufacturer. Some vehicles
require multiple units to clean the exhaust gases more thoroughly. When the catalyst
breaks apart it can clog the outlet of the catalytic converter causing the exhaust
to backup into the engine forcing low power or stalling. Visit -
In order for the converter to operate properly it must operate at a high
temperature. When a vehicle's engine is cool air is pumped into the exhaust system
to super heat the catalytic converter to aid in this heating process.
An oxygen sensor delivers feedback information which the PCM (computer) uses to determine
the amount of fuel injected into the engine. When this system malfunctions it can
cause the cat to overheat and break apart. Visit -
Oxygen sensor testing
When a converter fails replacement is necessary. Visit
- The catalyst in the catalytic converter can break apart causing low power
- The catalytic converter can get very hot causing a fire hazard when vehicle
is parked over dry brush.
Article first published 2016-02-03