Understanding the Parts of the Mustang Exhaust
The most common modification done to a Mustang next to buying new wheels, is on the exhaust. Whether you're swapping out your mid-pipe or getting a whole new system, one thing is constant: Mustang owners want true American Muscle sound and performance. This can be done by upgrading the parts of your exhaust. But, what are the parts of the exhaust?
It may seem like a silly question, but it's not! There is more to the exhaust system than just pieces of metal bolted together. Your exhaust performs many functions, but the most important ones are:
How does the exhaust system do these things? By pushing the nasty gases from your engine, through the pipes and mufflers, and out of your car.
There are three main components to the exhaust system. All Mustangs have the same set-up, regardless of generation.

You will hear manifolds sometimes referred to as headers. While they perform the same function, they are not exactly the same. So, what's the difference? A manifold usually has several holes converging into a common chamber. Headers generally have tubes that curve to join the exhaust ports to the exhaust pipe. This allows the gases to gently slide into the pipe, rather than slamming through the ports.
Manifold - Stock
Header - Aftermarket
GT Mustangs: Come stock with a pipe that has an H-formation (H-Pipe)
V6 Mustangs: Come stock with a pipe that has a Y-formation (Y-pipe).
Some aftermarket mid-pipes come in an X-formation and are called X-pipes.
The main function of the mid-pipe is to equalize the exhaust pulses. They are the
bursts of exhaust from the engine to the pipe which makes the system work
more efficiently, allowing the engine to produce more power.
All stock mid-pipes come with catalytic converters, or "cats". Cats remove the contaminants from the exhaust, making them emissions friendly. Aftermarket mid-pipes that are meant to be used off-road or for racing don’t have catalytic converters, and are called “off-road H- or X-pipes.” Off-road mid-pipes aren’t meant for street use and, depending on your state’s emissions laws, may not pass inspection.
Mufflers Made Simple
Mufflers are designed to reduce the noise your car makes when it’s running. There are three ways manufacturers do this:
Do Mufflers make Horsepower?
No. However, using a muffler with the best possible flow will help with the overall efficiency of the entire system. The more efficient your system is, the more power you have.
What are resonators?
They are similar to a muffler, but they are basically just a sound chamber. They are used for one of two reasons:
Most people use it to soften the volume, and recognize that there is little to no performance gain to be had.