How does exhaust connected to engine? [with Pdf]

Hey guys, I here at my friend’s four-wheelers workshop actually visited to know about the vehicle’s exhaust system. Actually, I and also almost most of the people only know that vehicle has an engine and gases are comes from the engine and released through the exhaust pipe (also known as tailpipe) but don’t know how these gases are coming from the engine to exhaust? how they are connected with each other? So I got a lot of information that I tried to share here.

The exhaust is connected to the engine with the help of a pipe that has a catalytic converter, Resonator, and Muffler. These devices are installed on the pipe that performs operations to reduce the noise level and pollution of the exhaust gases. Therefore the engine exhaust is connected to catalytic converter then to Resonator & Muffler then to the exhaust.

How does exhaust connected to engine

Why exhaust is connected to the engine?

When the combustion process is completed, burnt gases present in the combustion chamber are releases from the combustion chamber through the exhaust port but at that time the exhaust gas contains toxic gases, and also it creates large noise. So, as per rules and regulations given by the government, It is necessary to reduce the voice produced by the engine and remove the polluted elements from the exhaust gases.

Therefore, after the combustion, The burnt gases from the combustion chamber releases through the exhaust valve. These burnt gases from the exhaust valve pass through the pipe and then from the exhaust they are released into the atmosphere.

But, during passes through the pipe, burnt gases passes through the catalytic converter, resonator, and muffler which are installed on the pipe which aim is to improves the engine’s performance.  The catalytic converter works to reduce the emissions from exhaust gases & the Resonator and muffler helps to reduce the sound produced during engine exhaust.

Components located between exhaust and engine?

There are many devices located between the exhaust and engine which perform the particular operation. Some of these are as follows.

A] Exhaust manifold or Exhaust header

Exhaust manifold or Exhaust header
Credit: flickr

The exhaust manifold is the part that is connected to the exhaust ports of the cylinder and receives the hot burnt gases from the cylinder. It generally receives the gases from exhaust ports with the help of multiple pipes and collects them into a single pipe.

The other end of the exhaust manifold is connected to the Catalytic converter that are connected by the Down pipe. Hence, the hot burnt gases flows from the exhaust manifold to the Catalytic converter.

B] Catalytic converter

Catalytic converter

The Catalytic converter is the device that controls automobile exhaust emissions. It consists of the catalysts such as palladium, platinum, and rhodium.

It converts hazardous gases like Nitrogen oxides, Unburnt hydrocarbons, Carbon monoxide into less harmful gases such as Nitrogen, Oxygen, Carbon dioxide, H2O, etc.

The catalytic converter is located after the exhaust manifold and before the muffler since the catalytic converter works more efficiently at high temperature.

C] Muffler or silencer

Muffler or silencer

The muffler is the device that is used to reduce the loud sound waves of the exhaust. It is consists of the number of tubes

How exhaust is connected to engine?

  1. The engine’s multiple cylinders exhaust ports are connected to the Exhaust manifold.
  2. The Exhaust manifold is connected to the Catalytic converter with the help of Down pipe.
  3. The Catalytic converter is connected to the Resonator and Muffler with the help of Mid pipe or Cat-back.
  4. The Muffler & Resonator is connected to tail pipe.

How does exhaust system work?

Firstly, at the end of the power stroke, the exhaust valve opens and during the exhaust stroke, all the gases from the combustion chamber are expelled in the exhaust manifold through the exhaust port.

The exhaust gases from all cylinders come into the exhaust manifold and through the downpipe, they are flows to the catalytic converter.

The catalytic converter plays a significant role in reducing emissions. When the exhaust gases enter into the catalytic converter, a chemical reaction occurs between these gases due to catalysts present in the catalytic converter & In such a way, fewer harmless gases obtain at their output.

Then after the catalytic converter, the gases with high-intensity sound waves pass through the mid-pipe and enter into the Resonator and Muffler where it reduces the volume of the gases.

Finally, after the Resonator and Muffler, the gases are released into the atmosphere through the tail-pipe.

What will be happen if engine and exhaust are not connected?

If the engine and exhaust are not connected then the exhaust gases released from the engine will directly get spread into the atmosphere.

These gases contain polluted gases such as unburnt Hydrocarbons, Nitrogen oxides, Carbon monoxide, Sulphur oxides, particulates, and soot, Resulting in high air pollution as well as during the releasing of these gases from the engine large sound produces which results in noise pollution.

Therefore, It is necessary to have the engine connected to the exhaust to passes the combustion gases released from the engine. So, the exhaust system has a muffler, a catalytic converter Installed which helps to reduce such problems.

Frequently asked questions

  1. Where does the exhaust go directly from the engine?

    During the exhaust stroke, all the combustion gases from the combustion chamber first through the exhaust valve flows to the exhaust manifold and then they are further pass through the remaining part of exhaust system.

  2. What does your exhaust pipe connect to?

    The exhaust pipe is connected to the engine with a catalytic converter, muffler, resonator installed on this.

  3. What are the three parts of the exhaust system?

    The important three parts of the exhaust system are the Exhaust manifold, Catalytic converter, and Muffler. Also, the other parts used in the exhaust system are the Oxygen sensor, Resonator, Particulate filter, etc.

  4. What is the end of the exhaust called?

    The end of the exhaust is called as the tailpipe from where the exhaust gases are released into the atmosphere.

  5. Is a catalytic converter part of the exhaust system?

    Yes, a Catalytic converter is the main part of the exhaust system which plays a significant role in reducing the exhaust emissions from the automobile.

  6. Can you drive without an exhaust pipe?

    Yes, we can drive the vehicles without exhaust pipes but the problem is vehicle emissions are directly spread into the atmosphere without treatment which results in more air pollution.
    Also, vehicles become noisy without exhaust pipes, which generates a large volume hence that causes noise pollution.

  7. What is the pipe between the catalytic converter and muffler called?

    The pipe connects the catalytic converter and the muffler is called the “Cat-back”.

  8. Is a resonator the same as a catalytic converter?

    No, Resonator is different from the Catalytic converter.

  9. Can you drive with a faulty catalytic converter?

    Yes, we can drive the vehicle with a faulty Catalytic converter, But a faulty Catalytic converter means it does not work properly hence it will not reduce the emissions of vehicles and release harmful gases into the environment.

  10. Is a catalytic converter connected to a muffler?

    Yes, The Catalytic converter is connected to a muffler with the help of a cat-back pipe.

  11. Does removing a catalytic converter increase noise?

    Yes obviously, Removing a catalytic converter will increase the noise of automobiles.

  12. What happens if you remove exhaust silencer?

    If we remove the exhaust silencer from the automobile, It will generate large noise which causes noise pollution.


The Exhaust system is the system that is used in the car to releases combustion gases into the atmosphere by reducing its noise and polluted contents.

So, that’s all about the exhaust system that is located in the vehicle that is connected with the engine. Now you know how the engine and exhaust are connected. As per new inventions, there are some additional devices are connected to this exhaust system such as the EGR valve, Oxygen sensor, etc.

Pratik is a Graduated Mechanical engineer. He enjoys sharing the engineering knowledge learned by him with people.

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