Catalytic converters

 

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.