Car Exhaust System Explained- Parts, Design, Construction, Working & More

The automobile exhaust pipe, or car exhaust, is the part of the vehicle, in the form of a pipe, that takes the gas out of the vehicle's engine. A proper exhaust system is very important for your vehicle to be in good health. It not only removes the burnt gas-fuel mixture but also plays a major role in cleaning the emissions and hence reducing the noise generated by your car. 

Because it is so important to the overall performance of your car, you must understand how the car exhaust system works and how it is constructed.

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The Construction of a Car Exhaust

Parts of the System:

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Exhaust Manifold:

It is that part of the exhaust system which is connected directly to the engine. It collects exhaust gases and fuel and sends them into one pipe.

Oxygen Sensors:

It is the second part of the exhaust system and is put after the exhaust manifolds. They sense the oxygen level in the exhaust gas.

Pipes:

They act as a connecting link between other parts. Most of the time, they are created in such a way that high pressure doesn't cause much damage to them.

Catalytic Convertor:

It is located after the oxygen sensors or, in some cases, after the manifolds. It removes harmful gases like nitrogen oxide and carbon monoxide from the exhaust. 

Resonator:

It might not be present in most cars. If present, it is put after the converter. It helps in reducing noise in the long run.

Muffler/Silencer:

It is present in most vehicles. Similar to the resonator, it reduces noise. A silencer works for a wider range of sound than a resonator.

Tailpipe/Exhaust:

As is clear from the name, it is the final part/endpoint of the system. It removes the exhaust gas and exhaust fuel from the car.

Working of an Exhaust:

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Stage1:

The exhaust gases in a car are produced after the fourth cycle of combustion of fuels is completed. The first part of the exhaust system—manifolds—is connected to the engine. The manifolds have only one output. They collect and store all the exhaust gases, taken from all the chambers, in one pipe. A poppet valve is present to control the opening and closing of the exhaust manifolds.

Stage 2:

After the exhaust manifolds collect all the exhaust gas from all parts of the engine, it is then sent to the catalytic converter or the oxygen sensors via pipes. There, the level of useful oxygen is checked for performance analysis, and the catalytic converters change the harmful gases. Gases like NOx and CO are reduced and oxidised and get converted into harmless particles. 

Uses of stock pipes: Stock pipes cut the car's cost as they have tapers, which affect the exhaust gas pressure and cause back pressure, leading to performance reduction.
Use of oxygen sensors: The oxygen sensors measure the oxygen level in cars. If the exhaust has too little oxygen, this implies that the car is using too much oxygen from the fuel and vice versa.

Stage 3:

Another oxygen sensor is present after the catalytic converter. It is to ensure that the exhaust gases which have left the convertor are carbon dioxide (an oxidised form of carbon monoxide) and oxygen.

Resonators and mufflers reduce the noise produced by the engine by absorbing it. The last part of the system, the tailpipes, removes the exhaust from the car.