Cat-Back vs. Complete Exhaust Systems: Which One is Right for Your Ride?

By Daren Foertsch

Upgrading your vehicle’s exhaust system is one of the best ways to boost performance, improve sound, and increase fuel efficiency. One of the first questions enthusiasts face when it’s time to upgrade is whether to go with a cat-back exhaust system or a complete exhaust system.

Both options have their own advantages, and the best choice comes down to your performance goals, budget, driving needs and local emissions regulations. To help you decide, let’s take a closer look at how these two exhaust setups compare and which one best suits your ride.

Image: Valvetronic

A cat-back exhaust system refers to an exhaust upgrade that replaces everything from the catalytic converter back to the tailpipe. This typically includes the mid-pipes (if applicable), mufflers, resonators, and tailpipe. Since a cat-back system only replaces components after the catalytic converter, it does not include headers or downpipes, meaning the factory exhaust manifold and catalytic converter remain unchanged.

One of the biggest benefits of a cat-back system is improved sound. Upgrading to a cat-back system will give your vehicle a more aggressive exhaust note. The less restrictive design combined with high-flow mufflers allows the engine to breathe easier which gives it that deeper sound and can help increase power. While not as dramatic as a full exhaust system, a cat-back system can still improve horsepower and torque. 

Another benefit is that these systems are usually bolt-on installations, making them easier to install since they attach directly to your existing catalytic converter. Additionally, because cat-back systems don’t modify emissions-related components, they are legal in most states.

However, there are some downsides. The performance gains from a cat-back system are somewhat limited compared to a full exhaust upgrade. Since it doesn’t replace the catalytic converter or headers, it won’t unlock the maximum horsepower potential of your ride. If you’re looking for the maximum performance boost, you may need to consider a full system.

Image: R1 Motorsport

A complete exhaust system replaces everything from the engine’s exhaust headers all the way back. This means it includes new headers, high-flow catalytic converters, mid-pipes, a muffler, resonator, and the tailpipe, effectively replacing your entire stock exhaust system.

The biggest advantage of a complete exhaust system is it delivers maximum performance gains. Since it replaces restrictive factory headers with high-flow headers, exhaust scavenging is improved, allowing for better airflow and increased horsepower. 

A full system optimizes exhaust flow from the engine, leading to noticeable power and torque improvements. Additionally, a complete system delivers the most aggressive exhaust note possible and is ideal for high-performance builds, especially if you’re adding a turbo, supercharger, or other performance modifications.

However, a complete exhaust system comes with a higher cost. It is significantly more expensive than a cat-back system, and the installation process is far more complex, often requiring professional help.

Additionally, some full exhaust systems may not be street-legal in certain states due to modified catalytic converters, so it’s important to check local emissions regulations before making a purchase.

Both cat-back and complete exhaust systems offer great benefits, but the right choice depends on your goals. If you want an easy upgrade that improves sound and flow, go for a cat-back exhaust. If you’re looking for serious horsepower gains and a full performance overhaul, a complete exhaust system is the better option.

At Legends Auto Parts, we carry high-quality cat-back and complete exhaust systems from top brands to suit every truck owner’s needs. Check out our exhaust selection today and make your ride legendary!