What Does My Exhaust Actually Do?

Posted on by K&M Team


Every petrol or diesel powered vehicle has an exhaust – some have one, some have four, but they all serve the same purpose. However, what that purpose is can be unclear to a lot of people, especially if they don’t have specialist motoring knowledge or a keen interest in cars, bikes and trucks. This article will look into the job of an exhaust and why it is such an important part of so many vehicles.



An exhaust is made up of five main parts, each one vital to the effectiveness of the exhaust system and therefore the running of the vehicle:


Exhaust Manifold

The manifold is attached to the vehicles engine via the cylinder head. As it is the front of the exhaust system, it is tasked with venting the exhaust gases from each cylinder into one single pipe. Any excess fuel that is not burned in the engine is burnt by the manifold.


Oxygen Sensor

This component communicates with the on board computer in the vehicle, sending oxygen levels to the system, which in turn allows the car to control how much fuel is required in the engine for optimum fuel efficiency.


Exhaust Pipes

The visible part of the exhaust system, the pipes are the exit point for the exhaust fumes. Vehicles with eight cylinder engines will often have two exhaust pipes – one for the left cylinders and one for the right.


Catalytic Converter

This part is incredibly important for the environment, as it converts harmful carbon monoxide and hydrocarbons into carbon dioxide and water, making the exhaust more environmentally friendly. The converter is situated after the exhaust manifold, and it can in fact be illegal to drive a vehicle without a catalytic converter.



Without a muffler, the noise emitted by a vehicle is extremely loud, so these parts are fitted to every exhaust to dampen the sound. The muffler consists of a series of metal tubes called baffles, which the combustion soundwaves must travel through, losing their energy as they go. Other mufflers use fibreglass to absorb soundwaves, but some use both methods for maximum effect. Some drivers change the size of the muffler to give their vehicle a different, often louder sound.


Exhaust systems are incredibly important to vehicles for a number of reasons. Not only do they provide a safe method of exit for exhaust fumes, they also help reduce the environmental impact of the fumes and the noise of the combustion soundwaves. Without exhaust systems, our roads would be a lot louder, murkier and more dangerous.

Here at K&M Autocentre, we are proud to offer our expert services for a wide range of vehicles, from family saloon cars to sports cars and 4x4s. If you would like to know more about what we do, please feel free to get in touch with us today and we will be more than happy to help you.

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