To the untrained eye it might look as though car exhausts are just metal tubes that emit gases from your engine out into the atmosphere. While that is one of their main functions, the role of the exhaust system is far more complicated than that, but we’ve put together a handy guide that will tell you all you need to know about car exhaust parts and systems.
Depending on the make and model of your car, your exhaust system will vary in terms of the design and even the position, but they all work in essentially the same way. The main purpose of your car exhausts is to carry the emissions from the front of the vehicle away from the car through a series of pipes and boxes, and into the air.
Despite doing its job, to an extent, it is possible that some exhaust systems that might be damaged or worn, can prove to be illegal. A damaged exhaust can also lead to potentially harmful gases entering the cabin of the vehicle, which could cause serious health problems for you as the driver, and any passengers.
A lot of the most important car parts need to work at their optimum level to be classed as road legal by the police and insurers, but if the police feel as though your exhaust is emitting too much of the pollutant gas then they may require your car to undergo stringent testing before letting you on your way, or before making you get the damage repaired.
This means that it is vital that you understand the very basic workings of your exhaust system and how to spot any potential problems. With the emissions usually coming out of the rear of your vehicle, and at ground level, it can be difficult for drivers to be able to see these issues, but we will take you through a simple way of diagnosing and resolving any exhaust problems.
Exhaust Parts
There are a number of common exhaust parts that you will find in all systems.
Exhaust Manifold
This is the first major part in the exhaust system and it transports the gases from the engine into the exhaust system via the cylinder heads. It is usually made up of steel, aluminium or even cast iron in some cases.
Catalytic Converter
This particular exhaust part takes the harmful exhaust gases (such as carbon monoxide) and converts them into water vapour and carbon dioxide.
Oxygen Sensor
A small but crucial component of your car exhausts. The oxygen sensor, also known as a lambda sensor, is used to work out how much oxygen is located inside the exhaust, and the on-board computer can then establish just how much fuel should be added for the optimum fuel efficiency.
Exhaust Pipe
As the name suggests, this part carries all of the gas from the engine to the point where it is released into the atmosphere.
The Exhaust System Explained
Your exhaust system starts working the moment you turn the key in your ignition. The fuel is burned, powering the vehicle, and the gases are then transported away from the cylinder head by an exhaust manifold. This acts in a similar way to a funnel, ensuring that the gases move away from the engine and into the front pipe of the exhaust system.
From here they are moved through a catalytic converter, and the harmful carbon monoxide and hydrogen monoxide are removed and converted into inert gas. All of the gases then pass through a silencer that deflects the sound waves caused by the moving gases in the pipes so that you have a much quieter ride. If there are any particularly loud noises coming from your exhaust, the silencer may be the affected part.
At the end of the system, the gases are released through the tail pipe, which is the part that sticks out of the rear of the vehicle.
Common Exhaust Problems and Resolutions
It is highly recommended that you have your whole exhaust system checked twice a year so that you can identify any potential problems before they have the chance to worsen, as opposed to finding the problems when they are already at the point where they will need to be replaced as a matter of urgency.
Corrosion
One of the most common problems with any exhaust system, regardless of the make and model, is corrosion. Rust, as it is also known, wears away the metal over time and is brought about as a result of the rain and other fluids that come into contact with your car’s exhaust parts.
Once your exhaust starts to show signs of corrosion, it’s time to make a change. Sometimes parts can be welded to cover the affected area, but this is often nothing more than a quick-fix and the corrosion could still spread.
Hissing Noise
A hissing noise could be due to a crack in the exhaust manifold. As this key component is located at the very start of the exhaust system, it needs to be working at the optimum level at all times or it can have a knock-on effect for the rest of the exhaust. It is not the easiest of parts to locate at home, but a professional mechanic with an inspection area may be able to get underneath the car to identify the problem and to replace the damaged part.
Drop In Fuel Efficiency
If you notice that your fuel efficiency has started to drop, but you haven’t noticed a change in the performance of your car, then it could mean that your oxygen sensor is starting to wear. As it begins to tire – like most car parts – it will become less accurate (they tend to last around 60,000 miles), and as the main role of this component is to inform how much fuel is required, it could be costing you money.
Fortunately it’s quite easy to replace a damaged oxygen sensor. Simply locate and undo the affected sensor, compare the old one with the new, just for your own reference, and then connect the new one. Remember to use any diagnostic tools that you have available to make sure that the replacement has been a success.
For more expert advice and industry news, take a look at our other articles, and remember you can find over 130,000 affordable parts both in store and online, at Euro Car Parts.