An exhaust system is a set of metal pipes that carries away noxious emissions created by the combustion of gas usually from an automobile engine. The exhaust system must work properly for a vehicle to run reliably and safely. Modern exhaust systems typically clean up the gases before releasing them into the environment. Sometimes modifying the system helps the gases flow more smoothly and boost performance and efficiency.
When an automobile engine runs, it burns gas for power in a process called combustion. When combustion occurs inside the engine, harmful gases are given off as byproducts. These gases often leave the engine containing dangerous substances that can't be released unaltered into the surrounding air. For this reason, the gases must travel through an exhaust system that removes most of the hazardous substances first. The system also quiets a large amount of the noise from the running engine.
The primary components of an exhaust system include the exhaust manifold, pipes, catalytic converter, muffler, and tailpipe. These components work together to collect and transport the exhaust gases. If something goes wrong with the system, the gases may not flow correctly. This can cause problems with an engine's performance if the gases become trapped and unable to move through the system. Gases leaking out before the dangerous substances are removed may create a possible safety hazard, especially if they enter the passenger compartment of the vehicle.
The exhaust manifold is the first part of an exhaust system that gases travel through. The exhaust manifold gathers the gases from the different cylinders of the engine in a single location and combines them in one pipe before they travel on. The gases continue to move through the pipes toward the rear of the vehicle, pushed through continuously as more enter the system.
The hazardous gases are cleaned in the catalytic converter on the way through the exhaust. The catalytic converter removes harmful substances from the gases, thus making the remaining gas into a relatively harmless mixture that won't harm people or the environment. The next stop is the muffler, which quiets much of the noise from the running engine using sound deadening materials. Finally, the exhaust exits the system through the tailpipe.
There are modifications that can be made to a car's existing exhaust that can give a slight boost to engine performance. This is accomplished by reducing friction and resistance in the system which helps the exhaust travel more quickly and easily. This allows the engine to operate to its maximum potential. These modifications can include smoothing the insides of the pipes and replacing pieces of the system with specially designed aftermarket parts.