The exhaust system of your car is very important in dissipating gases that are created by the engine's operation. These gases are potentially harmful to the car occupants and the environment if not dealt with properly. To understand how the exhaust system works one must be aware of the individual components that make up the system as a whole.
The air pump forces compressed air into the exhaust manifold (a part to be explained shortly). The oxygen in this air aids in burning any of the unburned fuel and thus converting harmful carbon monoxide into carbon dioxide. The air pump is driven by a belt connected to the engine.
The exhaust manifold is a pipe that attaches to the cylinder head and directs the exhaust gases from the combustion chamber to the exhaust pipe. This component is likely located under the intake manifold. Most exhaust manifolds are made of cast iron but could be made of stainless steel or aluminum.
Since the cylinder head was mentioned above a quick definition is worth mentioning. A cylinder head is a metal part within the engine that covers the cylinders. It is attached to the top of the block and contains combustion chambers.
A catalytic converter is installed in the exhaust line between the exhaust manifold and the muffler. Its function is to convert the engine exhaust gases, such as carbon monoxide, into carbon dioxide and water. The catalytic converter really tries to prevent the noxious gases from becoming a pollutant in our atmosphere. That is why the converter is lined with chemicals that change the harmful gases into harmless ones before they are pushed out into the environment.
The most recognizable component of the exhaust system is easily the muffler. The muffler is made of metal and is connected to the underbody of the car between the catalytic converter and tail pipe. The true function of the muffler is to reduce the noise of the exhaust system. I am sure everyone has heard a car without a muffler and can tell the difference in noise decibels from a car that contains a muffler.
The engine combustion process is what creates the exhaust gases. The gases then leave the engine at extreme pressure which in turn generates a lot of noise. There is also a lot of noise created by the opening and closing of the exhaust valves. The gases then leave the engine at extreme pressure.The job of the muffler is to covert that sound energy into heat thus forcing the sound waves to dissipate their energy.
There are two types of muffler designs. Most mufflers use baffles to control or bounce the exhaust gases around and thus dissipate its energy and stifle the sounds. The baffles can consist of metal plates or tubes with a series of holes called chambers. This allows the pressure of the gases to be reduced and go out of the tail pipe much more quietly than when the gases entered the muffler. The second type uses pipe wrapped in metal or fiberglass which types absorbs some of the noise.
The final main component to the exhaust system is the tail or exhaust pipe. This is part that sticks out the backend of your car. The tail pipe consists of a long metal tube made of steel, stainless steel or aluminized steel. The tubing is attached to the muffler.
The tail pipe sticks out at the rear of your car in order to release the exhaust gases that have passed through the muffler, into the outside air. This is the end journey for the exhaust gases. And the last function of the exhaust system.
It is more common in modern cars to now include an oxygen sensor as part of the exhaust system. This sensor measures how much oxygen is present in the exhaust. With this reading the car's computer should calculate if fuel needs to be added or subtracted to obtain the best mixture for fuel efficiency. If this part is included with your exhaust system it will be mounted near the exhaust pipe or in the exhaust manifold.
There are many components that make up your car's exhaust system. The whole process is actually easy to understand once learning about each part individually. It is important for harmful gases to be carried away from the engine, quieted and let out of the car in a harmless way. Hopefully you now understand this process and system.