WHAT IS A CATALYTIC CONVERTER?
The major component for a mainstream exhaust system is the catalytic converter. It's connected to a single pipe of exhaust gases collected from the separate cylinders. The catalytic converter "cleans up" three of the less common, but more dangerous, exhaust waste products.
Most of what's produced by the combustion process are nitrogen gas, carbon dioxide, and water vapor. But there also are smaller amounts of nitrogen oxides, carbon monoxide, and hydrocarbons. You can even install the best empire exhaust systems to produce the best performance across a much broader RPM range.
WHAT DOES A MUFFLER DO?
Waste gases aren't the only things traveling through your exhaust system. So are sound waves. And it turns out that excessive noise has become a public health issue, even being linked to major heart problems.
Mufflers rely on a few main strategies for reducing noise pollution. One is to route the sound waves through tubes or chambers inside the muffler. The idea is to direct the sound waves so most end up canceling each other out. Additionally, sound-absorbing materials can be packed inside the muffler.
WHAT IS AN EXHAUST RESONATOR?
Some mufflers are specifically designed to tune the engine sounds to appeal to drivers. For example, part of the aggressive roar of a V8 engine comes from the way its muffler is designed.
There also are cars with separate exhaust resonators to take this concept to the next level. Generally located in the exhaust system ahead of the conventional muffler, an exhaust resonator isn't supposed to reduce the overall volume. Rather, it cancels out only the annoying frequencies and leaves the "good" ones as loud as ever.