Exhaust and Emissions

During normal engine operation, exhaust gases are created. When this exhaust leaves the engine, it is loud and contains gases and particulates than can be harmful to humans and can contribute to poor air quality. The exhaust system helps to quiet the exhaust and release it out of the back of the vehicle through the tail pipe. The emissions system helps your vehicle run more efficiently so less harmful gases are produced. But since a vehicle still produces harmful gases, the emissions system helps reduce those as well.

Emissions System
During normal vehicle operation, emissions are produced. While some of these emissions are harmless like water, heat, and oxygen, harmful byproducts—hydrocarbons (HCs), carbon monoxide (CO), and nitrogen oxide (NOx)—are also produced. One way the system reduces these harmful byproducts is by making the engine run more efficiently. The emissions system also recycles emissions back through the combustion process or converts them into harmless gases.

Modern emissions systems are complex and computer-controlled and they must meet the standards dictated by the EPA's Clean Air Act. Most states require emissions testing (smog checks) for vehicles that were made after 1975.

Exhaust System
The purpose of the exhaust system is to take exhaust gases from the engine and send them out of the vehicle through the tail pipe. It also helps reduce the noise produced by the combustion process.