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Car Exhaust System

Yash Gode
A good exhaust system of a car gives it power, reduces exhaust noise, controls emission, etc. Read on to know more about this system and its various parts.
In simple terms, a car exhaust system takes harmful emissions from the engine of the car, and safely emits it out without affecting the car and its passengers. Given are the vital components of this system.

Exhaust Systems Explained

The main components of an exhaust system are:
  • Exhaust Valve: This actually may not be considered as a part of the exhaust, but the process of releasing the spent gases starts from this valve, which further yields the way for the exhaust.
  • Exhaust Manifold: The exhaust manifold connects the exhaust valve in the cylinder head and combines the exhaust from each cylinder into one common pipe. The manifold is generally made of some alloy of steel, aluminum, and stainless steel, or these days from cast iron.
  • Oxygen Sensor: This is a content sensor fitted in almost all modern exhaust systems in a car to measure how much oxygen is present in the exhausted gases being released. This sensor also aids the fuel injection system to optimize the fuel inflow so that minimum oxygen proportion is obtained in the next round of exhausts.
  • Catalytic Converter: This is a chemical component of the exhaust which catalyzes a reaction between harmful carbon monoxide and hydrocarbons, to give carbon dioxide and water vapor. Some modern catalytic converters also act on harmful nitrogen oxides to minimize its percentage. It is mounted between the manifold and muffler.
  • Muffler: This is the most vital part of the sound exhaust system. The job of the muffler is to tone down the noise levels of the system. The combustion process is nothing but a series of explosions of gases being ignited under very high pressure. This process generates tremendous amount of noise that needs to be suppressed.
Mufflers have energy-obstructing baffles to bounce off the sound energy, thereby, quietening the noise. Fiberglass packing may also be used to absorb the sound.
  • Exhaust Pipe: This part carries the spent gas to the outer environment. It is usually made up of steel or stainless steel. These days, aluminized steel tubing is also used in making of exhaust pipes. It has better corrosive resistance than stainless steel, and it is also cheaper.

Things to Look Upon

Rusting is the worst problem with an exhaust system. It is caused by the moisture reacting with the metallic car parts. Taking frequent short trips will enhance this problem further as the water vapor does not get enough time to move out of the exhaust, and it cools off to liquid state again, thereby, rusting the metal. For those living in coastal areas, the salt in the water can add to the rusting woes. Its presence can speed up the rust-causing reaction.
Oxygen sensor problems can result in decreased fuel efficiency. Keep a habit of replacing the oxygen sensor after 50,000 miles of car run as these sensors tend to be inaccurate with time.
Problems with the muffler can lead to a lot of inconvenience, as the car's sound levels can exceed permissible levels. If some catalytic-converter issues arise, a mechanic might tell you to do without it, as it rarely makes a difference. But do not fall for this, and replace it if needed, as it is illegal to remove this component in most states, and you may be liable for a hefty fine.
As far as the prices of these systems are concerned, it can range from USD 50 for a single component to above USD 1000 for the entire exhaust system.
This is just a general overview; there can be a lot more to write on each and every component of the system of a car exhaust.