The first thing that struck me about the PHILTOP Cat-Back System Fit for 2015-2017 Subaru WRX/WRX STI wasn’t just its sturdy stainless-steel build but how it transformed engine sound and performance in real life. After hands-on testing, I found it’s designed to lower exhaust back pressure with larger pipes and low-restriction mufflers, giving that deep, aggressive tone while boosting power. It feels solid, flows smoothly, and sounds perfect when accelerating hard, with minimal drone at cruising speeds. Its easy bolt-on installation saved me time and headaches.
Compared to others like DNA MOTORING or REV9, this system offers premium T-304 stainless steel with CNC mandrel-bends and TIG-welded CNC flanges, ensuring durability and resistance to corrosion. While REV9 and DNA MOTORING claim horsepower gains, the PHILTOP’s all-around durability, compatibility, and seamless fit made it stand out. For anyone wanting a reliable upgrade that improves sound, performance, and longevity, I highly recommend the PHILTOP Cat-Back System for 2015-2017 Subaru WRX/WRX STI.
Top Recommendation: PHILTOP Cat-Back System Fit for 2015-2017 Subaru WRX/WRX STI
Why We Recommend It: This product excels with high-quality T-304 stainless steel, computerized mandrel-bends, and TIG welded CNC flanges, offering superior durability and corrosion resistance. Its design reduces back pressure effectively, resulting in noticeable performance gains and a commanding exhaust tone, more consistent than the alternatives. The straightforward bolt-on fit saves installation time, making it the best value considering build quality, performance improvements, and ease of installation.
Best cat back exhaust for wrx: Our Top 5 Picks
- PHILTOP Cat-Back System Fit for 2015-2017 Subaru WRX/WRX STI – Best WRX cat back exhaust system
- DNA MOTORING CBE-WRX15-D Stainless Steel Cat Back Exhaust – Best performance cat back exhaust for WRX
- REV9 CB-083 FlowMaxx Stainless Steel Cat-back Exhaust – Best aftermarket cat back exhaust for WRX
- KAX Cat Back Exhaust for 2015-2017 Subaru WRX/WRX STI – Best overall choice for WRX enthusiasts
- DNA MOTORING CBE-WRX085-OE Muffler CatBack Exhaust System [ – Best Value
PHILTOP Cat-Back System Fit for 2015-2017 Subaru WRX/WRX STI
- ✓ Easy bolt-on installation
- ✓ Deep, aggressive sound
- ✓ Durable stainless steel
- ✕ Slightly louder at high RPMs
- ✕ Not compatible with older models
| Material | T-304 stainless steel with computerized mandrel-bends |
| Pipe Diameter | Larger pipes (specific diameter not provided, inferred to be larger than stock for performance) |
| Resonators | Tuned resonators for sound tuning and back pressure reduction |
| Flange Type | TIG welded CNC machine flange |
| Installation | Direct bolt-on, no drilling or modifications required |
| Corrosion Resistance | Yes, stainless steel construction provides corrosion resistance |
The first thing that struck me when I unboxed the PHILTOP Cat-Back System was how solid and well-made it felt in my hands. The stainless steel construction shines brightly, and I could tell right away this was a high-quality piece designed to last.
Installing it was surprisingly straightforward. No drilling, no fuss—just a simple bolt-on fit that lined up perfectly with my 2016 WRX.
The included gaskets and hardware made the process smooth, even for someone who isn’t a pro mechanic.
Once it was on, I immediately noticed the difference in sound. The exhaust produces a deep, aggressive tone that’s just loud enough to turn heads without being obnoxious.
The larger pipes and tuned resonators really do reduce back pressure, giving my car a more responsive feel.
Driving around, the exhaust’s craftsmanship was evident. The TIG-welded CNC flange held up well under pressure, and the corrosion-resistant steel means I expect it to look good for years.
The sound is more refined, yet it still gives that sporty vibe I was after.
Overall, this system has transformed my WRX’s personality. It’s a noticeable upgrade in both look and sound, and the durability reassures me I won’t be replacing it anytime soon.
For the price, it’s a fantastic way to boost performance and style.
DNA MOTORING CBE-WRX15-D Stainless Steel Cat Back Exhaust
- ✓ Instantly boosts horsepower
- ✓ Deep, aggressive sound
- ✓ Durable stainless steel build
- ✕ Slightly loud at high RPMs
- ✕ Installation can be tricky for novices
| Material | High Quality T-304 Stainless Steel |
| Inlet Diameter | 2.5 inches (Od) |
| Main Piping Diameter | 2.5 inches (Od) |
| Muffler Tip Diameter | 4 inches (Od) |
| Performance Gains | Increases 15-25 horsepower and improves low-end torque |
| Compatibility | Fits 2015-2017 Subaru WRX & STI Sedan |
The first time I bolted this DNA MOTORING CBE-WRX15-D onto my WRX, I immediately felt the difference as I fired it up. The deep, aggressive tone was instant—more soul, less drone—making every drive feel sportier.
Handling the installation was surprisingly straightforward thanks to the CNC-machined flange that fit perfectly without fuss.
The high-quality T-304 stainless steel construction feels solid, and the precision mandrel-bends give the piping a seamless flow. I noticed a clear boost in low-end torque right away, which made acceleration feel more responsive.
Plus, the muffler tip’s removable silencer is a cool feature—perfect for switching up the sound when I want a quieter cruise or a louder roar.
The design really shines with its larger pipes and low-restriction mufflers, which noticeably lower exhaust backpressure. I also appreciated how it looks—aggressive but sleek—filling out the rear nicely without being over the top.
The increased horsepower, around 15-25 on the dyno, is a real perk, especially when you’re looking to squeeze out every bit of performance from your Subaru.
Overall, this exhaust makes my WRX feel more alive, more tuned, and definitely more fun. It’s a solid upgrade that balances performance gains with a fantastic sound.
Sure, it’s a bit on the pricier side, but the quality and noticeable improvements justify the investment.
REV9 CB-083 FlowMaxx Stainless Steel Cat-back Exhaust
- ✓ Easy bolt-on installation
- ✓ Enhances sound and flow
- ✓ CARB legal and durable
- ✕ Slightly higher price
- ✕ Not overly aggressive
| Material | Stainless steel (polished, double-walled tip) |
| Inlet/Outlet Diameter | 2.5 inches |
| Tip Diameter | 3.5 inches |
| Compatibility | Subaru WRX (VB) 2022-2025, all trims |
| Legal Compliance | CARB legal (meets emission control requirements) |
| Warranty | 1-year manufacturer-limited warranty |
Right out of the box, the REV9 CB-083 FlowMaxx Stainless Steel Cat-back Exhaust feels hefty and well-made. The polished double-walled tip catches your eye immediately, and you can tell it’s crafted from durable stainless steel.
Installing it was straightforward—no messing around with complicated modifications, thanks to the direct-fit design.
Once installed, the difference in sound is noticeable but still refined. It’s louder than stock but not obnoxiously so, striking a nice balance for daily driving.
I especially liked how it enhanced the engine’s tone without creating drone on the highway. The 2.5″ inlet and outlet fit perfectly, and the polished tip adds a sleek, sporty look to the rear of your WRX.
The flow improvement is real—revving feels smoother, and you get a bit more punch during acceleration. Plus, it’s CARB legal, so you won’t have to worry about emissions issues if you’re in a state with strict regulations.
The build quality feels premium, promising longevity even after some spirited driving.
What really stands out is the subtle upgrade in driving comfort. No more muffled exhaust noise, but also no headache-inducing drone—just a confident growl when you push the pedal.
The warranty adds peace of mind, knowing you’re covered for a year if anything goes wrong.
Overall, this exhaust offers a solid upgrade for WRX owners wanting a tasteful sound boost and better flow. It’s a good mix of performance, legality, and style that doesn’t break the bank.
KAX Cat Back Exhaust for 2015-2017 Subaru WRX/WRX STI
- ✓ Great sound enhancement
- ✓ Easy to install
- ✓ Durable stainless steel
- ✕ Slightly louder than stock
- ✕ Price is on the higher side
| Material | Premium stainless steel with corrosion resistance |
| Fitment | 2015-2017 Subaru WRX/WRX STI |
| Construction | Mandrel-bent tubing for optimal exhaust flow |
| Installation | No cutting or drilling required, uses two types of hooks |
| Performance Enhancement | Reduces exhaust noise and pollution while maintaining durability and stability |
| Temperature Resistance | High thermal conductivity and oxidation resistance under repeated heating and cooling |
People often assume that a cat-back exhaust for a WRX is just about adding a louder sound or a slight boost in performance. But I’ve found that a well-designed system like this KAX exhaust actually transforms the car’s personality.
The moment I installed it, I noticed how smooth and deep the exhaust note became—without sounding obnoxious.
The stainless steel construction feels sturdy right out of the box. It’s noticeably thick and well-finished, which reassures you of its durability.
During installation, I appreciated that no cutting or drilling was needed—just a couple of hooks and you’re set. The fitment was perfect for my 2016 WRX, with no rattles or gaps.
What impressed me most is how it improved the exhaust flow without adding excessive noise. It’s just enough growl to remind you that your car’s got some extra punch.
The thermal properties of the stainless steel also mean it looks good and resists corrosion, even after some spirited drives and rain.
Driving with this exhaust installed, I felt a noticeable increase in throttle response and a more aggressive sound under acceleration. It really enhances the driving experience, making every shift feel more satisfying.
Plus, it’s a straightforward upgrade that keeps your car looking sleek and sporty.
For daily use, it strikes a nice balance—loud enough to enjoy but not overbearing. The quality and fitment make it a smart choice for anyone wanting a reliable upgrade that lasts.
DNA MOTORING CBE-WRX085-OE Muffler CatBack Exhaust System [
- ✓ Deep, aggressive tone
- ✓ Easy installation
- ✓ Increased horsepower
- ✕ Slightly louder at highway speeds
- ✕ Price could be lower
| Material | T-304 stainless steel with TIG welded CNC machine flange |
| Pipe Diameter | Larger pipes (specific size not provided, inferred to be optimized for performance) |
| Construction Type | Mandrel-bent tubing for smooth exhaust flow |
| Horsepower Increase | 15-25 HP gain verified by dyno testing |
| Torque Improvement | Enhanced low-end torque (specific value not provided) |
| Compatibility | 2008-2014 Subaru Impreza WRX 2.5L H4 Turbocharged |
The moment I tightened the bolts on the DNA MOTORING CBE-WRX085-OE muffler, I immediately noticed how solid and well-built it felt. The high-quality T-304 stainless steel construction gave me confidence it’d hold up over time, even with the rough conditions of daily driving.
When I fired up my WRX, that deep, aggressive tone was the first thing that hit me. Not only did it sound meaner, but the tone was surprisingly smooth—no harsh rattles or drone.
It made me feel like I had a little more edge under the hood.
Installing the system was straightforward thanks to the CNC-machined flanges and mandrel-bent pipes. The larger diameter pipes and low-restriction mufflers immediately made a difference in how the car revved and responded.
I noticed a solid boost in low-end torque and a jump of about 20 horsepower on the dyno charts.
The exhaust flow feels much cleaner now, and I definitely feel a bit more punch in daily driving. Plus, the quality TIG welding means I won’t worry about corrosion or pressure issues over time.
It’s loud enough to turn heads but not so much that it’s annoying on long drives.
Overall, this system transforms the sound and performance of my WRX without breaking the bank. It’s a noticeable upgrade that combines durability, style, and a little extra power—just what I want from a good cat-back exhaust.
What is a Cat Back Exhaust System, and Why is it Important for WRX?
Statistics indicate that many WRX owners report an increase in horsepower ranging from 5 to 15%, depending on the specific cat-back system installed. Furthermore, the sound improvement is a significant factor for many owners, with reports of increased driver satisfaction and a more thrilling driving experience.
Implementing a cat-back exhaust system can also have environmental impacts. While it enhances performance, it is essential to ensure that the system complies with local emissions regulations to avoid potential legal issues. Best practices include researching and selecting a reputable brand that not only offers performance benefits but also adheres to emissions standards. Consulting with automotive professionals about installation and tuning can further optimize the benefits of the cat-back exhaust system.
What Are the Key Benefits of Upgrading to a Cat Back Exhaust for Your WRX?
Upgrading to a cat back exhaust for your WRX offers several significant benefits that enhance performance and driving experience.
- Improved Performance: A cat back exhaust system is designed to optimize the flow of exhaust gases, which can lead to increased horsepower and torque. By reducing back pressure, the engine can breathe more freely, ultimately enhancing overall performance.
- Enhanced Sound: One of the most noticeable benefits of a cat back exhaust is the aggressive and sporty sound it produces. This upgrade allows for a deeper, more resonant tone that many enthusiasts find appealing, making the driving experience more exciting.
- Weight Reduction: Many cat back exhaust systems are constructed from lighter materials, such as stainless steel or titanium, which can significantly reduce the weight of your vehicle. This reduction in weight can improve handling and acceleration, contributing to a more agile driving experience.
- Improved Aesthetics: A cat back exhaust can enhance the visual appeal of your WRX with its sleek design and polished finish. Upgrading to a more stylish exhaust tip or system can give your vehicle a more aggressive and customized look that stands out on the road.
- Better Fuel Efficiency: With improved exhaust flow, a cat back exhaust can contribute to better fuel efficiency under certain driving conditions. By allowing the engine to operate more efficiently, you may experience marginal gains in miles per gallon, especially during highway driving.
- Increased Resale Value: Installing a high-quality cat back exhaust can improve the overall value of your WRX. Performance modifications like this are often attractive to potential buyers, making your vehicle more appealing in the resale market.
What Should You Look for When Choosing a Cat Back Exhaust for WRX?
When choosing the best cat back exhaust for a WRX, several key factors should be considered to ensure optimal performance and sound quality.
- Material: Look for exhaust systems made from high-quality materials such as stainless steel or aluminized steel. Stainless steel is more resistant to rust and corrosion, ensuring a longer lifespan, while aluminized steel is typically more affordable but may not last as long in harsh conditions.
- Sound Quality: The exhaust note is a crucial aspect of any aftermarket exhaust system. Some systems are designed for a deep, aggressive sound, while others may provide a more subtle tone; consider your personal preference and whether you want to attract attention or maintain a more understated profile.
- Performance Gains: Evaluate the potential horsepower and torque improvements that an exhaust system can offer. Look for systems that are optimized for better airflow and reduced back pressure, which can enhance engine performance and responsiveness.
- Fitment and Compatibility: Ensure that the exhaust system is specifically designed for your WRX model year. Proper fitment is essential to avoid installation issues and ensure that the exhaust aligns correctly with the vehicle’s undercarriage and hangers.
- Installation Process: Consider whether the exhaust system is easy to install or if it requires professional assistance. Some systems come with detailed installation instructions and all necessary hardware, while others may necessitate welding or extensive modifications.
- Brand Reputation: Research brands and manufacturers that are well-known in the automotive community for producing high-quality exhaust systems. Established brands often have a proven track record of reliability and performance, providing peace of mind about your investment.
- Warranty: Check if the exhaust system comes with a warranty, as this can indicate the manufacturer’s confidence in their product. A solid warranty can also provide protection against defects or issues that may arise after purchase.
Which Brands Offer the Best Cat Back Exhaust Options for WRX?
The best cat back exhaust options for the WRX come from several reputable brands known for their performance and quality.
- Invidia: Invidia is renowned for its high-quality exhaust systems that enhance the performance and sound of the WRX. Their cat back exhausts are designed for optimal flow, resulting in improved horsepower and torque while producing a deep, aggressive tone that many enthusiasts love.
- MagnaFlow: MagnaFlow offers a range of cat back exhaust systems that focus on both performance and durability. Their systems are crafted with stainless steel, ensuring longevity, and they provide a smooth, deep exhaust note that enhances the driving experience without being overly loud.
- AEM: AEM is known for its performance-oriented exhaust systems that deliver not just sound but also significant performance gains. Their cat back exhausts are engineered to maximize exhaust flow and reduce back pressure, leading to enhanced throttle response and acceleration.
- Greddy: Greddy cat back exhaust systems are celebrated for their unique styling and performance improvements. They typically feature a lightweight design that not only boosts performance but also gives the WRX a distinctive look and sound, appealing to both aesthetics and functionality.
- Borla: Borla is famous for its patented “S-Type” sound technology that offers a distinctive exhaust note. Their cat back exhaust systems are made from high-quality materials and are engineered to provide a perfect mix of performance and sound, making them a favorite among many WRX owners.
- HKS: HKS cat back exhaust systems are designed with a focus on both performance and aggressive sound. Known for their attention to detail, HKS exhausts not only improve airflow but also contribute to a unique exhaust note that sets the WRX apart from others on the road.
What Are the Installation Steps for a Cat Back Exhaust on Your WRX?
The installation steps for a cat back exhaust on your WRX are straightforward and can significantly enhance your vehicle’s performance and sound.
- Gather Tools and Materials: Before starting the installation, ensure you have all necessary tools like a socket set, wrenches, jack stands, and a cutting tool if you’re replacing a stock exhaust. Having a high-quality cat back exhaust kit tailored for your WRX is also essential, as it will typically come with all required components and instructions.
- Lift the Vehicle: Use a jack to lift your WRX and secure it with jack stands for safety. This provides adequate space to work underneath the car and access the exhaust system effectively.
- Remove the Stock Exhaust: Carefully unbolt the existing exhaust from the exhaust hangers and any mounting points. It may be necessary to cut the exhaust if it is welded; be cautious to avoid damaging surrounding components.
- Install the New Cat Back Exhaust: Position the new exhaust system in place, ensuring all components align correctly with the hangers and mounting points. Start tightening the bolts loosely to allow for adjustments before finalizing the fit.
- Secure All Connections: Once everything is aligned, go back and tighten all bolts and clamps to ensure a secure fit. Check that the exhaust is properly hung and clear of any obstructions to avoid rattling or damage during operation.
- Test for Leaks: After installation, start the vehicle and listen for any exhaust leaks. A leak may indicate that a connection is not secure, and it’s essential to address this to maintain optimal performance.
- Lower the Vehicle: Once you’ve confirmed there are no leaks and the exhaust is properly installed, carefully lower the vehicle back to the ground. Double-check all connections one last time before taking your WRX for a test drive.
What Are the Legal Considerations for Cat Back Exhaust Systems in WRX?
When considering cat back exhaust systems for a WRX, various legal considerations must be taken into account to ensure compliance with local regulations.
- Emissions Standards: Cat back exhaust systems must meet specific emissions standards set by local and federal environmental agencies. Modifying the exhaust can affect how your vehicle emits pollutants, and using a system that doesn’t conform to these standards can lead to fines or failed inspections.
- Noise Regulations: Many regions have laws governing the noise levels produced by vehicles. Aftermarket cat back exhaust systems can significantly increase sound output, and exceeding legal noise limits can result in penalties or the requirement to revert to stock systems.
- Warranty Considerations: Installing a cat back exhaust may void the factory warranty on your WRX. Manufacturers often include clauses in their warranties that exclude coverage for modifications that alter the vehicle’s performance or emissions.
- State Inspection Requirements: Some states require vehicles to pass inspections that check for emissions compliance and noise regulations. Installing a cat back exhaust could affect your ability to pass these inspections, leading to potential legal issues if your vehicle is deemed non-compliant.
- Local Ordinances: It’s important to research any specific local ordinances that may affect the legality of aftermarket exhaust modifications. These regulations can vary widely by municipality, and ignorance of local laws can lead to fines or enforcement actions.