Catalytic Converter – (CAT)

Catalytic converters (also referred to as ‘cats') have been widely used in vehicle production for over 50 years, and are designed to reduce the emissions produced by your car. Catalytic converters change harmful substances in a car’s exhaust gasses, into less harmful substances like carbon dioxide and water vapor by means of chemical reactions.

As part of normal vehicle fuel combustion, emissions are expelled from the exhaust, with the main three being nitrogen gas, carbon dioxide and water vapor. Other harmful emissions can be found in the exhaust, such as carbon monoxide - a poisonous gas that is both colourless and odourless. Hydrocarbons or Volatile Organic Compounds (VOCs) are a major component of smog produced mostly from evaporated unburned fuel and nitrogen oxides. These are a contributor to smog and acid rain, which can cause irritation to human mucus membranes. Our car ECU tuning services may detect issues with your emission control systems.

So how do catalytic converters work?

In chemistry, a catalyst is a substance that causes or accelerates a chemical reaction without itself being affected. Catalysts participate in the reactions, but are neither reactants nor products of the reaction that they catalyse.

In the catalytic converter, there are two different types of catalyst at work: a reduction catalyst, and an oxidation catalyst. Both types consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimises the amount of catalyst required as the materials are extremely expensive. Some of the newest converters have even started to use gold mixed with the more traditional catalysts.

There are various types of catalytic converters. Firstly, there’s a simple ‘two-way’ oxidation catalytic converter which works to turn carbon monoxide into carbon dioxide and hydrocarbons (basically particles of unburnt fuel) to carbon dioxide and water.

There’s also more advanced ‘three-way’ catalytic converters, which are fitted to modern cars and do the same as the above while also reducing emissions of nitric oxide and nitrogen dioxide which, together, are more commonly known as ‘NOx’ - a major cause of localised air pollution.

Diesel vehicles typically have special catalytic converters to cope with the specific emissions from compression ignition diesel engines. As part of 4x4 diesel tuning services, we can diagnose issues with your catalytic converter and give your advice on solutions. 

These Diesel Oxidation Catalyst (DOC) units are routinely paired with additional exhaust treatment technologies such as Exhaust Gas Recirculation (EGR), Diesel Particulate Filters (DPF) to trap soot and Selective Catalytic Reduction (SCR) which use injections of Diesel Exhaust Fluid (DEF) like AdBlue urea solution to remove NOx. If you’re experiencing problems or have the CAT light showing on your dash; Eurotune have Catalytic Converter repair, removal, deletion & replacement services starting from just $395+GST. Call us today