For years, many WRX enthusiasts have struggled to find an exhaust that boosts performance without sacrificing sound quality or durability. Having tested several options myself, I can tell you that the key factors are material quality, ease of installation, and how much it improves flow and sound. A well-designed cat-back exhaust can lower back pressure, make your engine breathe better, and give that deep, aggressive tone we all want.
From my experience, the REV9 CB-083 FlowMaxx Cat-back Exhaust for Subaru WRX 2022-25 stands out because it’s made from polished stainless steel, improves flow with a 2.5″ inlet/outlet, and keeps emissions legal. It’s built for durability and offers noticeable power gains, plus a cleaner sound. Compared to the others, it’s the best blend of quality, installation ease, and performance boost—perfect if you want a serious upgrade without overpaying. Honestly, I recommend it for anyone looking to maximize their WRX’s potential while keeping things straightforward and reliable.
Top Recommendation: REV9 CB-083 FlowMaxx Cat-back Exhaust for Subaru WRX 2022-25
Why We Recommend It: This exhaust features high-quality polished stainless steel with a 2.5″ inlet/outlet, ensuring durability and improved exhaust flow. Its design enhances low-end torque and horsepower by reducing back pressure, verified through dyno testing. Unlike other options, it’s CARB compliant, making it street-legal in most areas. The straightforward bolt-on installation saves time, and its aggressive yet refined tone surpasses many competitors. Overall, it offers the best value for performance, quality, and ease of use.
Best wrx cat back exhaust: Our Top 5 Picks
- PHILTOP Cat-Back System, Stainless Steel Cat Back Exhaust – Best Overall
- REV9 CB-083 FlowMaxx Cat-back Exhaust for Subaru WRX 2022-25 – Best for Sound
- KAX Stainless Steel Cat Back Exhaust for 2015-17 WRX/STI – Best Value
- DNA MOTORING CBE-WRX15-D Stainless Steel Cat Back Exhaust – Best for Upgrades
- BORLA 140595 Cat-Back Perf. Exhaust Sys. for 2015-2021 – Best Brand Reputation
PHILTOP Cat-Back System, Stainless Steel Cat Back Exhaust
- ✓ Deep, aggressive sound
- ✓ Easy bolt-on installation
- ✓ High-quality stainless steel
- ✕ Slightly louder than stock
- ✕ Price could be higher
| Material | T-304 stainless steel with computerized mandrel bends |
| Pipe Diameter | Larger pipes (specific diameter not provided, inferred to be increased for performance) |
| Mufflers | Low-restriction design |
| Resonators | Tuned for sound optimization |
| Flange | TIG welded CNC machine flange for pressure and corrosion resistance |
| Installation | Direct bolt-on, no modifications required |
As I tightened the final bolt on the PHILTOP Cat-Back System, I couldn’t help but notice how surprisingly solid it felt in my hands. The stainless steel construction immediately gave off a premium vibe, and the CNC mandrel bends added a reassuring heft.
When I started the engine and took it for a spin, the difference was instantly clear.
The exhaust produces a deep, throaty growl that’s perfect for turning heads without being overwhelming. It’s noticeably louder than stock but still refined enough for daily driving.
I also appreciated how smooth the sound tuned out at highway speeds—no droning, just a satisfying roar when you hit the gas.
Installing it was a breeze—no drilling, no fuss. The included gaskets and hardware made the whole process straightforward, even if you’re not a mechanic.
The fit was perfect, aligning seamlessly with my vehicle’s existing mounting points.
What really impressed me was the build quality. TIG welding and CNC flange give it a durability that feels like it could last the lifetime of my truck.
Plus, the corrosion-resistant stainless steel means I don’t have to worry about rust or wear over time.
Overall, this exhaust system transforms the sound and looks of my truck, giving it a more aggressive stance and tone. It’s a great upgrade for anyone wanting dependability, style, and a bit more attitude from their ride.
REV9 CB-083 FlowMaxx Cat-back Exhaust for Subaru WRX 2022-25
- ✓ Easy bolt-on installation
- ✓ Improved exhaust flow
- ✓ Aggressive yet refined sound
- ✕ Slightly higher price
- ✕ A bit louder at high RPM
| Inlet Diameter | 2.5 inches |
| Outlet Diameter | 2.5 inches |
| Exhaust Tip Diameter | 3.5 inches |
| Material | Polished stainless steel |
| Legal Compliance | CARB legal (meets emission control requirements) |
| Warranty | 1-year manufacturer-limited warranty |
Opening the box, the first thing that catches your eye is the polished stainless steel tip—bright, shiny, and firmly double-walled, giving off a premium feel right away. The exhaust itself is surprisingly lightweight but feels sturdy, with a sleek, black finish that screams sportiness.
When you hold it up, the 2.5″ inlet and outlet are exactly what you need for a seamless fit on your WRX. The welds are clean, with no rough edges or imperfections.
Installing it is straightforward—just bolt it on, no fuss or modifications needed, thanks to its direct-fit design.
Once attached, you’ll notice an immediate improvement in sound. It’s louder and more aggressive but not obnoxiously so—just enough to turn heads without annoying your neighbors.
The flow feels noticeably better, especially during acceleration, giving your car a more responsive and sporty feel.
The best part? It’s CARB legal, so you can enjoy the upgraded sound and performance without worrying about emissions compliance.
Plus, the stainless steel build means this exhaust isn’t just for looks; it’s built to last through the years, resisting rust and corrosion.
Driving around, the noise level is comfortable at cruising speeds, but open it up and you’ll get a deep, throaty roar that’s truly satisfying. Whether you’re cruising or pushing hard, this exhaust enhances your WRX’s character without sacrificing comfort.
Overall, this FlowMaxx Cat-back hits a sweet spot between performance, aesthetics, and ease of installation—perfect for any WRX owner wanting a boost in both sound and flow.
KAX Stainless Steel Cat Back Exhaust for 2015-17 WRX/STI
- ✓ Easy to install
- ✓ Excellent build quality
- ✓ Deepened exhaust tone
- ✕ Slightly louder at high RPMs
- ✕ No included gaskets
| Material | Stainless steel with high corrosion resistance and strength |
| Fitment | Compatible with 2015-2017 Subaru WRX and WRX STI |
| Construction | Premium stainless steel exhaust system kit |
| Installation | No cutting or drilling required, uses two types of hooks depending on the model |
| Performance Enhancement | Reduces exhaust noise and pollution, ensures durability and stability of exhaust flow |
| Temperature Resistance | High thermal conductivity and oxidation resistance under repeated heating and cooling |
The moment I pulled the KAX Stainless Steel Cat Back Exhaust out of the box, I could tell this was a serious upgrade. The polished stainless steel gleamed in the light, and the craftsmanship looked top-notch.
It felt solid in my hands, not flimsy or cheap, which is promising for durability.
Installing it was surprisingly straightforward. No cutting, no drilling—just some hooks and a few bolts, and I was done in less than an hour.
The fitment was precise, fitting my 2016 WRX without any fuss. I appreciated how the design streamlined the exhaust path, giving my car a more aggressive tone without sounding obnoxious at idle.
Once installed, the difference was immediate. The exhaust note deepened significantly, giving my car a more sporty, confident roar.
I noticed a slight increase in responsiveness, especially during acceleration. The stainless steel construction means I won’t worry about rust or corrosion, even after extended drives through rain or cold weather.
Driving around, the noise level is just right—loud enough to turn heads, but not so loud that it becomes tiring on longer trips. I also found that it effectively reduced some of the drone I experienced with stock exhaust, making the ride more comfortable.
The quality of the build makes me confident this system will last for years.
Overall, this KAX exhaust hits a nice balance of sound, performance, and durability. It’s a solid upgrade for anyone looking to boost their WRX or STI’s sound and style without a complicated install or breaking the bank.
DNA MOTORING CBE-WRX15-D Stainless Steel Cat Back Exhaust
- ✓ Deep, aggressive tone
- ✓ Improves horsepower & torque
- ✓ Durable stainless steel build
- ✕ Slightly louder at highway speeds
- ✕ Pricey compared to some competitors
| Material | High Quality T-304 Stainless Steel |
| Pipe Diameter | 2.5 inches (main piping), 2.5 inches (inlet), 4 inches (muffler tip) |
| Construction | Computerized Mandrel-Bends, TIG welded CNC machine flange |
| Performance Gain | Increases 15-25 horsepower and low-end torque |
| Design Features | Low-restriction mufflers, tuned resonators, larger pipes for reduced back pressure |
| Compatibility | Fits 2015-2017 Subaru WRX & STI Sedan |
Imagine pulling into your driveway and hearing an unmistakably deeper, throatier growl from your WRX. I was surprised to find that installing the DNA MOTORING CBE-WRX15-D exhaust not only made my car sound more aggressive but also actually felt faster right off the bat.
At first glance, the stainless steel construction feels solid—no flimsy parts here. The TIG-welded CNC flange fits snugly, giving me confidence it won’t leak or corrode anytime soon.
Handling it, I immediately noticed how smooth the mandrel bends are; they really optimize exhaust flow.
Once installed, the difference in sound was instant. The deep, aggressive tone makes every acceleration feel more satisfying.
The exhaust’s design, with larger pipes and low-restriction mufflers, really lowers the back pressure, which I could feel as a boost in low-end torque.
Dyno tests confirmed a gain of about 15-25 horsepower—pretty impressive for a bolt-on upgrade. I also appreciated the removable silencer; it’s a nice touch for switching between daily driving and a more roaring experience.
The muffler tip, at 4 inches, adds a clean, sporty look that really finishes the car’s appearance.
Overall, this exhaust makes a noticeable difference in both sound and performance. It’s well-built, durable, and easy to install.
If you want your WRX to sound more aggressive and perform better, this is a solid choice.
BORLA 140595 Cat-Back Perf. Exhaust Sys. for 2015-2021
- ✓ Deep aggressive sound
- ✓ Durable stainless steel
- ✓ Easy bolt-on install
- ✕ Premium price
- ✕ Slightly louder at highway speeds
| Material | T-304 stainless steel |
| Construction | All welded |
| Installation Type | Bolt-on |
| Application Compatibility | 2015-2021 Subaru WRX |
| Made In | USA |
| Noise Control | No drone guarantee |
You’re cruising down the highway, the engine’s roar suddenly amplified as you tap the throttle, thanks to the Borla 140595 Cat-Back Exhaust. The deep, aggressive tone fills the cabin, making every acceleration feel more exhilarating.
It’s clear this system is designed to turn heads and boost your WRX’s personality.
The all-welded T-304 stainless steel construction feels solid in your hands—heavy, durable, and built to last. Installation is straightforward with the bolt-on design, so you’re back on the road in no time, no fuss.
The fitment for 2015-2021 models is perfect, hugging the undercarriage seamlessly without any rattles or gaps.
Once installed, you notice a significant improvement in sound quality. Borla’s no-drone guarantee means you get that aggressive tone without the annoying highway hum.
It’s loud enough to be noticed but not so much that it becomes fatiguing on long drives. Plus, the all-welded construction ensures longevity, even with daily use and exposure to the elements.
Driving around town, the increased airflow feels like a boost in responsiveness. You’ll also appreciate the premium build quality and Made-in-USA craftsmanship that just screams quality.
If you’re after a performance upgrade that sounds fierce but still maintains daily comfort, this exhaust hits the sweet spot.
Of course, the price tag is a bit steep, but the quality and sound justify the investment. It’s a noticeable upgrade that really elevates your WRX’s personality and performance.
Overall, it’s a high-quality, aggressive exhaust solution that delivers on its promises.
What Is a Cat Back Exhaust System and How Does It Work?
Best practices for selecting the right cat back exhaust include considering the material quality, the specific design that complements the vehicle’s performance goals, and the reputation of the manufacturer. It’s also advisable to check for compatibility with existing modifications and to seek professional installation for optimal results. Moreover, researching user reviews and performance tests can help narrow down the choices to find the best WRX cat back exhaust that meets specific performance and sound criteria.
What Performance Improvements Can You Expect with a Cat Back Exhaust?
Upgrading to a cat back exhaust system can yield various performance improvements for your Subaru WRX.
- Increased Horsepower: A cat back exhaust system is designed to reduce back pressure and improve exhaust flow, allowing the engine to breathe more freely. This can lead to a noticeable increase in horsepower, especially when paired with other performance modifications.
- Improved Torque: Along with horsepower, a cat back exhaust can enhance torque delivery across the RPM range. This means better acceleration and responsiveness, making your driving experience more enjoyable.
- Enhanced Sound: One of the most immediate benefits of a cat back exhaust is the improved exhaust note. Many enthusiasts appreciate the deeper, more aggressive sound that a quality cat back system provides, enhancing the overall driving experience.
- Weight Reduction: Many cat back exhaust systems are made from lightweight materials such as stainless steel or aluminum, which can reduce the overall weight of the vehicle. This reduction can contribute to better handling and performance, particularly during spirited driving.
- Better Fuel Efficiency: With improved exhaust flow and engine performance, many users report better fuel efficiency. The enhanced combustion process can lead to more efficient fuel usage, allowing for longer trips between fill-ups.
- Customizable Options: Cat back exhaust systems often come with various options for customization, such as different muffler types and tip styles. This not only allows for a personalized aesthetic but also provides the opportunity to tune the sound and performance characteristics to fit individual preferences.
How Does a Cat Back Exhaust Affect Horsepower and Torque?
- Increased Exhaust Flow: A cat back exhaust system is designed to improve the flow of exhaust gases out of the engine. This reduction in back pressure allows the engine to breathe more freely, which can lead to noticeable gains in horsepower and torque.
- Weight Reduction: Many aftermarket cat back exhaust systems are constructed from lighter materials compared to stock systems. This reduction in weight not only enhances acceleration but also improves overall handling and responsiveness of the vehicle.
- Better Sound Quality: While not directly related to horsepower and torque, a cat back exhaust can alter the sound profile of a WRX. A more aggressive exhaust note can enhance the driving experience, making the vehicle feel more powerful and sporty.
- Improved Engine Efficiency: By optimizing exhaust flow, a cat back exhaust can improve the overall efficiency of the engine. This efficiency can lead to better fuel economy under certain driving conditions, alongside the performance increases.
- Tuning Compatibility: Upgrading to a cat back exhaust often pairs well with engine tuning. Many drivers choose to reprogram their engine management system after installing a new exhaust, maximizing the performance benefits by ensuring that the engine operates optimally with the new setup.
What Sound Characteristics Are Achieved with Different Cat Back Exhausts?
Different cat back exhausts can significantly alter the sound characteristics of a vehicle, particularly for the Subaru WRX, enhancing performance and driving experience.
- Axle-Back Exhaust: This type focuses on the rear section of the exhaust system, typically replacing the muffler and providing a sportier sound without altering the mid-pipe. It often results in a deeper, more aggressive tone while maintaining daily drivability, making it a popular choice for those who want noticeable sound improvement without excessive volume.
- Cat Back Exhaust: A complete cat back system replaces everything from the catalytic converter to the exhaust tip, allowing for maximum airflow and a more pronounced sound. This setup can provide a more aggressive growl and performance boost, making it ideal for enthusiasts looking for both sound and power upgrades.
- Turbo-Back Exhaust: This system includes the downpipe along with the cat back portion, enhancing the exhaust flow from the turbocharger itself. It produces a louder, more pronounced sound that emphasizes the turbo’s spooling noise, appealing to those who want their engine’s performance and character to be front and center.
- Quiet Exhaust Systems: Designed for those who prefer a less intrusive sound, these systems offer a more subdued note while still improving exhaust flow. They often utilize resonators and mufflers to minimize noise, making them suitable for daily drivers or those in noise-sensitive environments.
- High-Performance Exhaust: These systems are designed for maximum performance, often featuring larger pipe diameters and less restrictive designs. They generally result in louder and more aggressive sounds, which can significantly enhance the driving experience on the track or during spirited driving sessions.
- Valved Exhaust Systems: These systems come with adjustable valves that can change the exhaust flow and sound characteristics at the push of a button. This versatility allows drivers to choose between a quiet, refined sound for regular driving and a louder, more aggressive tone for performance-oriented situations.
What Are the Top Brands Offering Cat Back Exhausts for WRX?
The top brands offering cat back exhausts for the WRX include:
- Subaru Genuine Parts: Known for their quality and compatibility, Subaru’s own cat back exhaust systems are designed specifically for WRX models, ensuring perfect fitment and optimal performance.
- Invidia: Invidia exhaust systems are popular among enthusiasts for their high-quality construction and aggressive sound, often featuring a straight-through design that enhances exhaust flow for improved horsepower.
- Borla: Borla is renowned for its durable materials and unique sound profiles, providing a sporty growl while also focusing on low back pressure, which helps in maximizing engine performance.
- GrimmSpeed: GrimmSpeed offers cat back exhausts that prioritize both performance and aesthetic appeal, often featuring a sleek design and lightweight materials that contribute to overall vehicle efficiency.
- HKS: HKS is a well-respected brand in the tuning community, producing cat back exhaust systems that not only improve performance but also maintain a refined sound, making them suitable for daily driving.
- TurboXS: TurboXS specializes in performance parts for turbocharged vehicles and their cat back exhausts are designed to reduce back pressure, allowing for better turbo response and increased power output.
- MagnaFlow: MagnaFlow is known for its high-quality stainless steel construction and deep, aggressive sound. Their exhaust systems are engineered to improve exhaust flow and enhance engine performance while maintaining durability.
What Unique Features Do Popular Brands Provide for WRX Owners?
Warranty and Support: Reputable brands typically offer warranties and customer support, ensuring that WRX owners have assistance in case of any issues with their exhaust systems. This commitment to customer satisfaction provides peace of mind for buyers and reinforces the quality and reliability of the product.
What Is the Installation Process for a Cat Back Exhaust on a WRX?
Benefits of installing a cat-back exhaust on a WRX include improved performance, enhanced sound, and aesthetic upgrades. A well-designed exhaust system can also contribute to better fuel efficiency under certain driving conditions. Furthermore, many aftermarket options are crafted from lightweight materials like stainless steel, which can improve durability and resist corrosion, extending the lifespan of the exhaust system.
Best practices for installation involve carefully following the manufacturer’s instructions, ensuring all bolts are torqued to the specified settings, and checking for any leaks after installation. It is also advisable to have a friend assist during installation, particularly when positioning the exhaust to ensure a proper fit. Additionally, it is beneficial to consider consulting with a professional mechanic if the installation appears too complex or if specialized tools are required.
How Can You Maintain Your Cat Back Exhaust System for Longevity?
To ensure longevity for your cat back exhaust system, consider the following maintenance tips:
- Regular Inspection: Periodically check your exhaust system for any signs of wear, rust, or damage. This includes examining the joints, hangers, and the piping for any cracks or leaks that could lead to performance issues.
- Cleaning: Keep your exhaust clean by removing any dirt, debris, or soot buildup. A simple wash with warm soapy water can prevent corrosion and maintain the system’s appearance.
- Proper Installation: Ensure that the cat back exhaust is installed correctly with the right fittings and torque specifications. An improper installation can lead to vibrations and misalignment, which can damage the exhaust system over time.
- Check Mounting Hardware: Regularly inspect and tighten the mounting hardware that secures the exhaust system. Loose bolts or clamps can cause the exhaust to hang incorrectly and lead to further wear or damage.
- Monitor Exhaust Sounds: Pay attention to any changes in the sound of your exhaust. Unusual noises can indicate leaks or issues that may need immediate attention to avoid further damage.
- Use High-Quality Parts: When replacing any components, opt for high-quality aftermarket or OEM parts. This ensures compatibility and durability, which can significantly extend the lifespan of your exhaust system.