Most vehicles need catalytic converters not only so they perform at their best, but also because it's the law. Here's how they work and why they are required.

The front honeycomb piece of a three-way catalytic converter is coated in a precious metal called rhodium. Its role is to break down the NOx into nitrogen and oxygen. Three-way plus air converters ...

More advanced ‘three-way’ catalytic converters are fitted to modern cars and these do the above while also reducing emissions of nitric oxide (NO) and nitrogen dioxide (NO2) which together are ...