Let’s get to the basics. We’ll start by asking what is a cat-back exhaust? Starting from the engine, exhaust is pushed through the manifold. After that point the flow through exhaust pipes, catalytic converters, more piping, the muffler and eventually out the tailpipe. A full exhaust kit would replace everything after the manifold, and a cat-back replaces everything after the catalytic converter.

There are many reasons to replace or modify your existing exhaust system; whether you’re looking to gain a better exhaust note, performance, or even clearance.

Replacing the whole exhaust system does make sense as it would be one whole unit by one brand as opposed to two separate brands, or two different styles of exhaust systems. The biggest reason to replace the cat-back is because you don’t have to get involved with removing or replacing the cat. 

In most states, post emissions vehicles require the use of a catalytic converter, and swapping to a full system may eliminate it meaning Johnny Law will do his best to keep your rig off the road. This may not be the worst case scenario for you guys and gals who intend to stay off-road, but for those looking to drive their Jeep to and from work, school, or even to the next mud pit it can be a major pain in the neck. Buying a full kit with cats can also be considerably more expensive.

That being said, you might also wonder how well these kits sound and perform. They may still be a bit choked by the cat, although their design allows for them to provide maximum flow rates.

Paired with a proper set of headers makes for a flow rate only topped by outlawed setups. The muffler is where most of the sound is coming from, and as long as there is a muffler, no matter how aggressive, you’ll be steering clear from the law. For the most part. This means you will still get the low rumble you’re looking for. 

Let’s take a step back. We covered flow sound and other topics, but clearance was mentioned and that may have raised an eyebrow or two. How could changing the exhaust help at all with clearance? When you’re off the beaten trail some obstacles can point the nose of the Jeep straight up in the air. 

As the front end gets further from the ground the rear end gets closer. The bumper isn’t the only thing that can get hung up on the ground, and tearing off a perfectly good exhaust system can be rather irritating and cost you money you didn’t intend on spending.

There are some exhaust systems that stop or turn down before the rear axle as opposed to exiting at the rear of the vehicle. This kit keeps the exhaust far from the rear bumper keeping it out of the way of rocks, stumps or whatever else it is you’re trying to climb over in the woods. 

Materials are the most important quality that differs across these exhaust kits. This is because the materials used can dictate just how long the exhaust will live. Aluminum is something of the entry-level material, whereas stainless is a bit more on the high end.

The material doesn’t have any direct effect on the sound quality or flow rate, which is wonderful. Really, when it comes to deciding which is best for you there are a few things to take into consideration.

First and foremost you should consider where you live or where your Jeep will spend the majority of its life. If it’s in the rust belt, stainless is the way to go. If your Jeep won’t see salt or harsh conditions that much then aluminized is perfect. 

Another variance in types would be the layout of the exhaust itself. What’s available to you truly does depend on the type of Jeep you have. 

• YJ: This year Jeep has the fewest types available to it. That isn’t to say that you’re without a paddle though. Shorter exhausts are available to this particular Jeep, which as mentioned before is super desirable when it comes to clearance.
• TJ: Much like the earlier YJ the types available to it are a bit limited. Your choices really vary when it comes to length. The selection is just a bit broader as it has more aftermarket support
• JK: The JK is the newest and most popular Jeep so it’s no surprise the aftermarket supports it the best. Here you have the option to choose shorter exhausts, exhausts with the muffler relocated, and even dual exhausts. The exhaust is split at the rear muffler, and it’s due to the location of the factory muffler, giving aftermarket suppliers more options. In fact, the JK can use an axle-back exhaust system, which is an entire discussion in itself

Of course sound and performance are two of the main reasons one would usually upgrade the exhaust on any vehicle. That being said, it’s always a good idea to upgrade the intake system or add a computer programmer to work in combination with this upgrade.

What’s a bit unique to Jeeps is clearance can be gained from just swapping out the exhaust system for something a bit shorter. If you’re putting yourself into situations where the tailpipe is in danger the next thing to start taking a hit is the bumper. Upgrading to a heavy-duty rear bumper or giving the vehicle more lift are some of the next logical steps for you.