What is the purpose of an exhaust emmision system?

The purpose of an exhaust emission system is to reduce the amount of harmful pollutants released into the atmosphere from an internal combustion engine (like those in cars, trucks, and other vehicles). It does this by treating the exhaust gases before they exit the tailpipe. These pollutants include:

* Carbon monoxide (CO): A toxic, odorless, and colorless gas.

* Hydrocarbons (HC): Unburned fuel that contributes to smog formation.

* Nitrogen oxides (NOx): Gases that contribute to smog, acid rain, and respiratory problems.

* Particulate matter (PM): Tiny soot particles that can cause respiratory problems.

The system achieves this reduction through various components, such as catalytic converters, oxygen sensors, and other emission control devices which chemically transform or filter out these harmful substances.