Q: Are Harmful Emissions Reduced by a Car's Exhaust System?

asked by on

Are harmful emissions reduced by a car's exhaust system?

The automobile exhaust system has been around as long as the car itself. The purpose of the original exhaust system was to divert gases from the the combustion process away from the engine and operator. The purpose of today’s exhaust systems is the same but with added tasks.

During combustion, the air and fuel mixture are burned under high pressure and with the aid of a spark plug. This process creates gases that are expelled via the exhaust system. These gases are made up of hydrocarbons, nitrogen, carbon monoxide, nitrogen oxides, and oxygen. Several decades ago, the government realized that some of these gases are quite harmful. They don’t just affect us, but also the planet as a whole through what we now know as the greenhouse effect. This led to stricter emission regulations, which led to the birth of the catalytic converter.

Today’s exhaust systems consists of piping, exhaust manifold (bolted to the cylinder head), muffler, tail pipe, oxygen sensors, and as of 1975, a catalytic converter. The exhaust gases are pushed out of the combustion chamber by the piston through the exhaust manifold. It is then sampled by an oxygen sensor which tells the vehicle’s computer if there was too much or not enough fuel, before going through the catalytic converter. Then it is sampled by yet another oxygen sensor, which is for catalytic monitoring. The next component is the muffler, which minimizes noise, and then it goes out the tailpipe.

As stated earlier, it is in the catalytic converter that emissions are controlled. There two kinds of converters: two-way and three-way converters. Two-way converters have two tasks. One is the oxidation of carbon monoxide to carbon dioxide. The other is the oxidation of hydrocarbons (unburned fuel) to carbon dioxide and water. The three-way does much the same but also controls the emission of oxides of nitrogen (NOx), which is the precursor to acid rain and smog.

It is the catalytic converter (which is part of the exhaust system) that is responsible for reducing harmful emissions. Therefore, if you notice any problems with the catalytic converter, you should have it replaced by a certified mechanic.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Are Harmful Emissions Reduced by a Car's Exhaust System?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: What Types of Metals Are Used to Make Exhaust Systems?

Chances are good that your exhaust system is made from 400-series steel. Cast iron is used for the exhaust manifold (stock). Aluminized steel is often used in aftermarket exhaust systems. In addition, a wide range of other metals can be...

Q: Emissions light comes on and goes off.

Hi. Emissions codes and emission problems are sometimes very difficult to diagnosis and pin point what exactly is causing the problem. Because of this it sometimes requires extra labor time to fix the emission problem properly. The good thing about...

Q: Muffler rattling at lower RPM

What you want to do is jack it up and get under there with a rubber mallet, have somebody start listening to the rattle, and hit them up with the mallet. After this, the mufflers will often no longer rattle....

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.