GMC Sierra 1500 Cat-Back Exhausts Explained

When making any kind of modification to your GMC Sierra, emissions need to be kept in mind. Catalytic converters are a part of the vehicle’s emissions system, and need to be left intact for the truck to be deemed road-worthy in the eyes of the law. This is why cat-back exhausts are so popular. They replace everything behind the catalytic convert, meaning you can get the benefits of aftermarket exhaust parts without crossing the law.

Making this modification is a pretty big deal. It can cost quite a bit of money, so you’re going to want to know what you have to gain from making this upgrade. There are three major reasons you would want to do this.

• Sound 
• Performance
• Increases lifespan of the exhaust

There are plenty of other reasons to make this upgrade but these really are the heart of the decision. If you’re still not convinced let’s crack open each one of these factors to explore the benefit of each. 

Sound: Sound is the first thing you will notice when you make this upgrade. Factory pipes are a tad bit on the restrictive side and the muffler is lacking in aggressiveness. A cat back exhaust will upgrade you to better flowing pipes and a muffler combination to get you that low rumble you’ve been looking for.

Performance Gains: You stand to make some performance gains as well. The high rate of flow doesn’t just improve the sound note. Engines are essentially air pumps; to make power they need to move a certain amount of air. It’s just as important to move the expelled fuel combination from the combustion chambers as it is to get it in there. Simply speaking, the better your engine can breathe, the more power it can make. Cat-back exhausts will help make that happen.

Materials: The materials used in these can be a major benefit. Odds are you’ll be exposing your 4x4 Sierra to snow fairly often (assuming you’re in the northern/northeastern parts of the county). If you’ve lived in the rust belt long enough or any area where road salt is used, you know how quickly vehicles tend to rot. The first thing to go most times is the exhaust.

Most cat-back exhausts are available in different materials. Stainless steel being one of them. Stainless steel will hold up longer in road salt than the factory exhaust will, and if you don’t want to fix your exhaust every couple of years this upgrade has your name all over it.

Aluminized steel is another popular material used on these exhaust kits. It’s treated to prevent corrosion, but won’t hold up as long as stainless will. This has no effect on the sound or the flow rate. It does typically cost less. This makes it perfect for you guys working on a budget. It also works perfectly for our friends to the south who don’t regularly see the horrors of road salt. 

Dual exhaust flows better and sounds better than single exhaust. Switching out the factory single pipe on your Sierra for duals is made easy with these kits. Depending on your generation of truck, though, this process is achieved differently. 

• 2007-2013 GMC Sierra 1500

For this Generation of GMC trucks, splitting the exhaust is done in a simple yet effective manner. A single pipe runs from the cat to the muffler. It is then split at the muffler and to pipes run to the rear of the truck. This design is easy to install and despite its simplistic design, gives noticeable gains in flow and sound. 

• 2014-Present

The latest models of GMC trucks use the same type of dual-exhaust design as we saw on earlier trucks. There is another option though. Instead of using one muffler to split the exhaust, a y-pipe is used just after the connection to the factory exhaust system. 
This allows for two pipes to run to the back with a muffler on each.

This design allows for much better airflow and a way more aggressive exhaust note. It may require a bit more effort to be mounted properly, but it is as close to running true duals as you can get before having to make major modifications to the existing exhaust system.

Single pipes are not to be ruled out entirely when it comes to performance gains and sound. Some single pipes can come with pipe sizes up to and over 3 inches in diameter. This is a sure way to get maximum flow from the exhaust system. Some mufflers offerings on these kits are extremely aggressive. This kind of setup can be the closest you can get to running a straight pipe without breaking the law. 

One major advantage of choosing a cat-back exhaust is they do not mess with the emissions requirements of the Sierra 1500. This, of course, keeps them street legal. That isn’t to say their only place is on the beaten path. They can relocate the exit location of the tail pipe. Moving the exit from behind the bumper to just before the rear tire gives a unique advantage to those of you looking for added clearance. You can safely climb over obstacles without having to worry you may rip off or pinch shut the exhaust system.