What Is a Cat Back Exhaust System

If you're anything like us at RaceStage, you live for the sound of a perfectly tuned engine, sharper throttle response, and squeezing every bit of performance out of your ride. One of the most popular mods among car guys (and girls) is upgrading to a cat back exhaust system—and for good reason.

What Does a Cat Back Exhaust System Mean?

The term “cat back” refers to all the components of the exhaust system that are located after the catalytic converter. This typically includes the mid-pipe, resonator, muffler, and tailpipe. It doesn’t touch your catalytic converter, so it usually stays emissions-legal—win-win.

What Does a Cat Back Exhaust System Do?

A cat back exhaust system reduces restriction in the exhaust flow, letting gases escape faster and more efficiently. That means your engine breathes better. Better breathing = more power, better throttle response, and usually a nicer growl from the back end.

How Does a Cat Back Exhaust System Improve Performance?

Here’s the real reason you're here: performance.

Swapping in a cat back exhaust system improves performance by reducing backpressure and increasing exhaust flow. When your engine doesn’t have to work as hard to push exhaust out, it frees up horsepower and torque—especially at higher RPMs.

You might also notice:

• Quicker throttle response

• Slight gains in horsepower (5–15hp depending on setup)

• Better fuel efficiency under some driving conditions

It’s not just about the numbers though—it's about the driving feel. The whole car wakes up.

What Does a Cat Back Exhaust System Sound Like?

Let’s talk sound. A cat back gives your car a deeper, throatier tone, and depending on the system and your engine, it can go from mildly aggressive to straight-up racecar loud.

Want something refined for daily driving? Go for a resonated system. Want to wake up the neighborhood? Non-resonated or straight-through mufflers are your friends.

What Is a Full Cat Back Exhaust System?

A full cat back exhaust system includes everything from the catalytic converter back:

• Mid-pipe (or Y-pipe/X-pipe on dual systems)

• Resonator

• Muffler(s)

• Tips

Full systems are bolt-on, tuned for optimal flow, and usually engineered to reduce weight compared to stock.

What Is a Cat Back Performance Exhaust System?

This is just a fancier name for the same thing—a cat back exhaust system designed specifically to increase performance. These are often made from stainless steel or titanium, mandrel-bent for smooth flow, and tuned for sound and power gains.

How to Install a Cat Back Exhaust System

If you've got a jack, some tools, and a few hours, this is totally a DIY mod. Here's the basic process:

1. Lift the car safely (jack stands or a lift)

2. Unbolt the stock exhaust from the catalytic converter back

3. Remove any hangers or brackets holding the old exhaust

4. Fit your new cat back exhaust system using the supplied clamps, gaskets, and hangers

5. Tighten everything down and double-check for leaks

Torque specs and specific steps will depend on your car model, so check your instructions or hit us up for help.

How Much Does a Cat Back Exhaust System Cost?

It really depends on the brand, material, and car model. Here’s a rough breakdown:

• Entry-level systems: €300–€600

• Mid-range (stainless steel): €600–€1,200

• High-end (titanium or performance brands like Akrapovič, Remus, Milltek): €1,200–€3,000+

Pro tip: Don’t cheap out. A well-made exhaust lasts longer, sounds better, and performs like it should.

Will a Cat Back Exhaust System Void My Warranty?

In most cases, no. Because a cat back system doesn’t touch emissions-critical components like the catalytic converter or sensors, it typically won’t void your warranty.

However, if you have a very strict dealership or warranty provider, always double-check. The EU Block Exemption Regulation protects your right to use aftermarket parts—as long as they don’t directly cause a failure.