In
a world full of copycats we have the original.
Increasingly
today's cars are designed for optimum performance by virtue of their
engine management. The fuelling curves designed for these cars are
mapped for the back pressure presented by the catalytic converter
and exhaust system. Indiscriminate fitting of a smaller aftermarket
cat can lead to unbalancing of these settings, and may cause a reduction
in brake horsepower or premature failure of the brick.
We have developed
our remanufacturing process using the standards applied in California
(CARB).
It is essential
that the cause of the failure of the original cat be established
before fitting of the next one. Otherwise your warranty may be invalidated,
and the cat will fail prematurely
There are many
causes for failure. The best route to finding your cause is to have
the vehicle checked by a qualified diagnostics technician. The ability
to check the vehicles overall health is aided by a good engine diagnostics
analyser which can check fuel injection duration, manifold pressure,
spark strength, timing, emissions etc. The old cat should be examined
for any fluid ingress, that could be oil, water, or antifreeze which
indicates more serious engine problems. Leaded petrol in even small
quantities will cause almost immediate failure of the cat. Often
the petrol is used unknowingly when the spare can from the garage,
normally reserved for the lawn mower, is innocently used, Even such
a small quantity can be fatal. If you are in any doubt as to whether
lead was used in the petrol mix (it only takes a fractional amount)
a test kit is available. Part number bb5031 is list price 40 for
10 tests or 110 for 100 tests.
The purpose
of any catalytic converter is to reduce harmful emissions from the
exhaust of a combustion engine. It accomplishes this through a combination
of heat and a precious metal catalyst that causes the harmful emissions
to either oxidize or reduce to safe elements in the exhaust flow.
If the engine is out-of-tune and not calibrated to OEM specs, the
catalytic converter's efficiency is greatly diminished and could
lead to a converter failure.
The precious
metal catalyst is bound to an extruded ceramic honeycomb substrate.
The ceramic has hundreds of flow channels that allow the exhaust
gasses to come in contact with a maximum amount of surface area
where the catalyst reaction takes place. The catalyst must come
in direct contact with the exhaust gasses for the reaction to take
place. If the ceramic inside your converter becomes clogged or coated
with carbon, lead or oil, then the converters efficiency is greatly
reduced.
There are three
basic types of automotive catalytic converters; Two-Way, Three-Way
and Three-Way + Air. Each type uses a slightly different method
and chemistry to reduce the harmful elements in exhaust emissions.
Early model converters used a pelletised catalyst, but most modern
converters are now designed with a free-flowing honeycomb ceramic
catalyst. The type of converter required on a particular vehicle
varies with model year, engine size and vehicle weight. Some vehicles
even make use of more than one type of converter or a pre-converter
to meet emission reduction standards.
A Two-Way converter,
used on American cars between 1975 - 1980, oxidizes unburned harmful
hydrocarbons and carbon monoxide into water and carbon dioxide.
The first vehicles with catalytic converters had Two-Way reduction
only capabilities.
A Three-Way
converter is a triple purpose converter. It reduces nitrous oxides
into nitrogen and oxygen. And, like the two-way converter, it oxidizes
unburned harmful hydrocarbons and carbon monoxide into water and
carbon dioxide.
A Three-Way
+ Air converter performs the same functions as the Three-Way converter.
It oxidizes and reduces. The difference is the addition of secondary
air between the two internal catalyst substrates that improves the
oxidation capabilities of the converter. The secondary air is pumped
into the middle of the converter between two separate catalyst coated
ceramic substrates. The front ceramic performs the reduction and
the back ceramic performs the oxidisation. Its like having two converters
in one.
Each of the
three types of converters mentioned above have a common need in
order to function properly. Each needs to reach a minimum operating
temperature before any emission reduction or oxidation takes place.
This warm-up period immediately after a vehicle is started is when
the catalytic converter is least efficient and the vehicle expels
the most pollutants. Some vehicles employ a pre-converter in the
exhaust system immediately after the manifold to help during this
warm-up period. The pre-converter's small size and proximity to
the engine allow it to heat up and start functioning in less time
than the main converter. It also pre-heats the exhaust gasses and
helps the main converter reach operating temperature sooner.
Core dealers
always required for catalytic converters.
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