Explained: What does a car exhaust do?

To the average driver, the exhaust is the little pipe that sticks out the back of their car and pumps out the hazardous gases that the government is desperate to clamp down on. It’s also known for producing some of the nicest sounds on the road, when done correctly. But, what actually is the exhaust system, and how does it work exactly? Let Scrap Car Comparison guide you through all you need to know in the latest part of our Car Care guide

Dual exhaust pipes on a custom car with rear spikes and teal paint. Custom cars in Southern California summer 2017

How does a car exhaust system work? 

While many people only think of an exhaust as the tailpipe, the exhaust system itself is actually made up of a number of pipes working across four key components; the exhaust manifold, the catalytic converter, the muffler and the exhaust pipe. The system kicks in when fumes expelled from the engine make their way into the exhaust manifold and are sent down a pipe into the catalytic converter. The catalytic converter then gets to work and converts the poisonous gases from the engine into less harmful substances.

After the catalytic converter has done its thing, the remaining gases make their way into the muffler, which acts as a way to quieten the hundreds upon hundreds of miniature explosions taking place every minute. It’s here where you can alter the sound by manipulating the amount of air that’s allowed to pass through. This is where the term “tuning” comes from – the more air that’s allowed through, the raspier and louder the note. When done well these can create some of the finest sounds around, although when done poorly they can be outright annoying – and is one of the reasons “boy racers” get such a bad rep.

The exhaust tip, or tailpipe, is the final stage of the process and is what most people will think of when you mention an exhaust. These tailpipes expel the remaining gases and final remnants of the combustion process.

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Symptoms of exhaust fumes in your car 

If exhaust fumes are getting into the cabin of your car, then they could cause some significant issues to your health. Exhaust fumes can cause irritation to your eyes and respiratory tract. Prolonged exposure to the fumes, which can include harmful gases such as carbon monoxide, could lead to coughing and breathlessness, and long-term exposure could lead to an increased chance of lung cancer.

How to fix an exhaust smell in your car

If you do find that you can smell exhaust fumes in your car, the first thing to do is to make sure it’s not another car around you. If you’re sitting in traffic or waiting at the lights, it could simply be that the smell from a car around you has sneaked in through your air conditioning.

If the smell doesn’t disappear once you’re back on the open road, then it’s time to pull over – driving with an exhaust leak is not only going to be extra polluting, but could be, as we’ve previously mentioned, extremely dangerous to your health. The most likely culprit would be an exhaust leak, which could come from any number of locations within the exhaust system, and even then it could be anything from corrosion to a loose joint, or even physical damage from an accident. Whatever the reason, pinpointing the source could be an incredibly difficult task and if you’re not well versed in mechanics, it’s best to take it to a garage as soon as possible to be absolutely safe.

Do electric cars have exhausts?

As electric cars are entirely powered by batteries, there is no need for an exhaust system, so you will not find a tailpipe on any Teslas or modern EVs. You will find one on a hybrid electric, however, as these cars feature a traditional internal combustion engine alongside the battery power unit. 

Can you drive a car without an exhaust?

Physically there is nothing stopping you from driving without an exhaust as it will not have any effect on the way the engine works, however in terms of your own safety it is not advisable at all. As mentioned above, exhaust fumes can be incredibly harmful to your health and you could be causing yourself serious damages further down the line as a result of prolonged exposure. On top of that, as per the Road Traffic Act 1988, you will be driving against the law if you drive with a broken, or missing, exhaust system. The exhaust sits under the designation of ‘the condition of the motor vehicle or trailer, or of its accessories or equipment’, meaning it must be kept in good working order without falling foul of the law.

Get the best price for your car with Scrap Car Comparison

If your car has a broken exhaust, or you know that the system is likely to cause enough problems to make your next MOT test more difficult, then it may just be easier overall to scrap your car, get rid of the problem and use the cash to start afresh with something new – maybe even an electric car so exhausts are a problem of your past. 

With Scrap Car Comparison’s industry-leading service, we can find the very best price for your car in under 60 seconds, and with our buyers being based all over the country, no matter where you call home, we’ll be able to provide collection direct from your door. Before you know it the car will be out of your hair and your bank account will have a nice lump of cash sitting in it waiting for you.

Get started today and find out just how much your old car could be worth.

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