Over the years, car manufacturers have been trying to find ways to reduce the harmful pollutants produced by vehicles. In 1975 they came up with the catalytic converter – and this is now the most important part of a car’s emission control system. In 1993 it became the law in the UK for new cars to be sold with catalytic converters in order to meet European emissions standards; now cars are often produced with multiple cats as standards become more stringent. The catalytic converter is beneficial not just to the environment but also to your car’s performance. However, it’s essential to have it checked regularly as faulty cats are expensive to repair. The Lambda sensor works in conjunction with the catalytic converter to determine how much oxygen the car is using, so this also should be checked if you have an exhaust issue.