A catalytic converter is a vehicle emissions device that converts toxic pollutants in exhaust gases to less toxic pollutants. Catalytic converters are used in internal combustion engines fuelled by either petrol or diesel. The purpose of any catalytic converter is to reduce harmful emissions from the exhaust of an internal combustion engine.
This is accomplished by a combination of heat and a precious metal catalyst that causes the harmful emissions from the exhaust to either oxidize or reduce to safe elements. If the engine is out of tune and not adhering to the manufacturers specs, the catalytic converter’s efficiency is greatly reduced and can lead to a failure of the converter.
The precious metal catalyst is bound to a ceramic substrate held within the converter.
The ceramic allows the exhaust gasses to come in contact with a maximum amount of surface area where the catalyst reaction takes place.
If the ceramic inside your converter becomes clogged or coated with carbon, lead or oil, then the converter’s efficiency is greatly reduced.
The oxygen sensor or Lambda sensor is a sensor which is located above the catalytic converter. This monitors the percentage of oxygen present in exhaust gases and transmits information to the engine management system or electronic control unit (ECU) which help reduce carbon emissions.
The ECU (Electronic Control Unit) — using information obtained from the oxygen sensor — constantly adjusts the air/fuel mixture so that the cleanest and most efficient combustion is achieved under all operating conditions.
Sometimes, a ‘failed’ catalytic converter can be due to a fault in the engine management system. In these circumstances a new catalytic converter may not rectify the problem.
So the oxygen sensor, catalytic converter and ECU all work together to help to achieve the lowest possible output of dangerous and polluting gases.
Lack of servicing the engine, not replacing the air filter on a timely basis can result in a shorter life or damage to the catalytic converter. This is because unburnt fuel can find its way into the cat and severely damage it. The replacement cost of a cat is very expensive, a new catalytic converter can cost up to €2000 and testing the catalytic converter is an important part of the NCT test.
If your catalytic converter requires checking or changing, Team AutoCentre is here to help – You deal direct with your selected local Team AutoCentre.