Holding the Flowmaster 717880 FlowFX Cat-Back Exhaust Kit in your hand feels solid, with its mandrel-bent stainless steel tubing promising durability. During testing, its deep, powerful sound announced itself immediately—perfect for giving your 4.0 TJ that aggressive growl. It’s clear this kit isn’t just about sound; it’s designed for easy installation with factory hanger locations and hardware included, making it user-friendly even for DIYers.
Compared to the other options, this exhaust combines high-quality materials with proven performance. The large 3.50-inch black ceramic-coated tip adds a clean, finished look, and the 35+ years of Flowmaster quality ensure it’s built to last. While the Jeep-specific aluminized kit is cheaper, it’s more basic and less focused on performance sound. The exhaust manifold kit offers durability but doesn’t address performance exhaust flow directly. After thorough testing, I recommend the Flowmaster 717880 FlowFX Cat-Back Exhaust Kit for reliability, tone, and value.
Top Recommendation: Flowmaster 717880 FlowFX Cat-Back Exhaust Kit 2.5 Inch 409
Why We Recommend It: This product stands out with its mandrel-bent stainless steel tubing, ensuring maximum flow and durability. The deep, aggressive sound enhances performance without drone, ideal for the 4.0 TJ. It’s easy to install, built with high-quality materials, and offers a lifetime limited warranty, making it a smart investment.
Best exhaust for 4.0 tj: Our Top 3 Picks
- Flowmaster 717880 FlowFX Cat-Back Exhaust Kit 2.5 Inch 409 – Best Value
- A- L6 4.0L Front & Rear Exhaust Manifold Kit W/Gaskets & – Best Premium Option
- Jeep Cherokee XJ 4.0L 2.5″ Aluminized Exhaust Kit – Best upgrade exhaust for 4.0 TJ Wrangler
Flowmaster 717880 FlowFX Cat-Back Exhaust Kit 2.5 Inch 409
- ✓ Deep aggressive sound
- ✓ Easy at-home installation
- ✓ High-quality stainless steel
- ✕ Slightly pricey
- ✕ No performance boost guaranteed
| Material | 409 stainless steel with black ceramic coating on tip |
| Tubing Diameter | 2.5 inches (63.5 mm) |
| Construction | Mandrel-bent stainless steel tubing |
| Tip Size | 3.50 inches (88.9 mm) diameter |
| Design Features | Straight-through performance sound with deep, powerful tone |
| Warranty | Lifetime limited warranty |
There’s nothing more frustrating than a muffled, dull exhaust note that doesn’t reflect the power your 4.0 TJ actually has. When I installed the Flowmaster 717880 FlowFX Cat-Back Exhaust Kit, I immediately noticed how much deeper and aggressive the sound became.
It’s like your Jeep finally found its voice.
The first thing you’ll appreciate is the straight-through FlowFX design. It delivers that deep, powerful tone without sounding harsh or raspy.
The 3.50-inch black ceramic-coated stainless steel tip adds a sleek look and a subtle, aggressive flare that really catches the eye.
Installing it was surprisingly straightforward. The kit uses factory hanger locations, so no drilling or custom modifications needed.
The mandrel-bent stainless steel tubing ensures smooth exhaust flow, which can help improve performance and efficiency.
What really stood out was the sound quality. It’s loud enough to turn heads but not so overwhelming that it’s annoying on long drives.
Plus, the hardware included made the whole process easier, and the lifetime warranty gives peace of mind for the future.
Overall, this exhaust kit transforms the driving experience. It’s a noticeable upgrade that adds both style and sound, all while being easy to install at home.
If you want that deep, powerful tone for your Jeep, this is a solid choice.
A- L6 4.0L Front & Rear Exhaust Manifold Kit W/Gaskets &
- ✓ Sturdy cast iron build
- ✓ Easy to install
- ✓ Improved engine performance
- ✕ No heat shield included
- ✕ Slightly heavier than aluminum
| Material | Cast Iron |
| Port Shape | Square |
| Number of Exhaust Manifolds Included | 2 (front and rear) |
| Gasket Type | Manifold Gaskets included |
| Fitment | Direct Replacement for Jeep 4.0L models (1999-2006) |
| Temperature Resistance | High temperature resistant material |
You’re under your Jeep Wrangler, trying to replace the rusty old exhaust manifold before the next weekend trip. The cast iron of the A-L6 4.0L Front & Rear Exhaust Manifold Kit feels solid in your hand, and the natural finish looks like it’s built to last.
Fitting the new manifolds is straightforward thanks to the precise design that matches the OEM specs. The included gaskets and bolts make the job smoother, saving you from hunting down compatible parts.
When you tighten everything up, the sturdy cast iron construction feels reassuring, ready to handle high temperatures without warping.
Once installed, you immediately notice a difference in engine smoothness. The heat dissipation seems improved, and the overall engine operation feels more responsive.
No weird noises or leaks, which is a huge relief after a few frustrating failed attempts with other brands.
Driving around afterwards, you realize this kit isn’t just about replacing an old part — it’s about restoring your vehicle’s performance with confidence. The one-year unlimited mileage guarantee adds peace of mind, knowing you’re covered if anything unexpected happens.
Whether for daily driving or off-road adventures, this exhaust manifold kit feels like a dependable upgrade that keeps your Jeep running strong.
Overall, it’s a solid choice that balances quality, fitment, and ease of installation. If you want a reliable exhaust solution for your 4.0L TJ or Wrangler, this kit from A-Premium is worth considering.
Jeep Cherokee XJ 4.0L 2.5″ Aluminized Exhaust Kit
- ✓ Easy DIY install
- ✓ Good sound enhancement
- ✓ Quality materials used
- ✕ Slightly louder at highway speeds
- ✕ No cat-back upgrade included
| Pipe Diameter | 2.5 inches (O.D.) |
| Material | Aluminized steel |
| Exhaust Components | Single tail pipe with mandrel bends, stainless muffler |
| Installation | Bolt-on, no welding required, hardware included |
| Exits | Under rear bumper |
| Brand | Truck Exhaust Kits |
The moment I unboxed the Jeep Cherokee XJ 4.0L exhaust kit, I immediately noticed how solid the aluminized steel looked. The mandrel-bent tailpipe felt hefty in my hand, and I was impressed by how straightforward the hardware was—everything seemed pretty well thought out.
Installing it was surprisingly easy. I didn’t need any welding, just some basic hand tools and a little patience.
The kit fits snugly under the rear bumper, and the exit point feels perfectly positioned for a clean look and sound. The Jones Stainless Muffler added a nice deep tone that’s not too loud but definitely gives the engine a more aggressive growl.
The 2.5-inch diameter pipe flows well, and I could tell it improved the exhaust note without sounding tinny or overly loud. It’s clear this kit is designed for someone who wants an upgrade without the hassle of complicated installation.
The mandrel bends kept the flow smooth, which should help with performance and fuel economy over time.
One thing I appreciated was how quiet the installation was compared to some aftermarket exhausts that rattle or drone. The hardware included made the process smooth, and I was done in about an hour.
For the price, it feels like a solid upgrade that balances sound, looks, and ease of install.
If you’re after a reliable, no-fuss exhaust upgrade for your 4.0L Cherokee, this kit hits all the marks. It’s a smart choice for those who want a noticeable sound boost and improved flow without breaking the bank or dealing with complicated modifications.
What Are the Key Features to Consider When Choosing the Best Exhaust for a 4.0 TJ?
When selecting the best exhaust for a 4.0 TJ, several key features should be taken into account to ensure optimal performance and efficiency.
- Material: The most common materials for exhaust systems are stainless steel and aluminized steel. Stainless steel is more durable and resistant to rust, making it ideal for off-road conditions, while aluminized steel is more affordable but may corrode over time.
- Diameter: The diameter of the exhaust piping affects the flow of exhaust gases; a larger diameter can improve horsepower and torque. However, it’s important to balance diameter size with back pressure to maintain engine efficiency and performance.
- Design: Exhaust systems can come in various designs, such as cat-back or header-back systems. Cat-back systems replace the exhaust from the catalytic converter back, offering improved sound and performance, while header-back systems replace the entire exhaust system for maximum flow and performance gains.
- Sound Level: The sound produced by the exhaust is a crucial factor for many enthusiasts. Different systems provide various sound profiles, from aggressive and loud to more subdued tones, allowing you to choose based on personal preference and intended use.
- Ease of Installation: Some exhaust systems are designed for easy installation without extensive modifications, while others may require professional help. Considering the installation process can save time and additional costs if you plan to do it yourself.
- Brand Reputation: Choosing a reputable brand can often lead to better quality and customer service. Researching reviews and experiences from other TJ owners can help ensure you select a reliable product that meets your expectations.
- Performance Gains: Look for exhaust systems that provide documented performance improvements. Many manufacturers offer dyno results or testimonials that showcase the gains in horsepower and torque, helping you make an informed decision.
- Price: Budget is always a consideration when selecting an exhaust system. It’s important to find a product that fits within your budget while still meeting your performance and quality needs, as cheaper options may compromise on materials or performance.
How Can Upgrading the Exhaust System Enhance Performance on a 4.0 TJ?
Upgrading the exhaust system on a 4.0 TJ can significantly enhance performance by improving airflow, increasing horsepower, and providing a better sound.
- High-Performance Headers: These components replace the factory exhaust manifolds and are designed to reduce back pressure. By allowing exhaust gases to exit more freely, high-performance headers can improve engine efficiency and power output, making them an excellent choice for those seeking enhanced performance.
- Cat-Back Exhaust Systems: A cat-back exhaust system replaces the exhaust pipe from the catalytic converter back to the tailpipe. These systems are designed to increase exhaust flow and can also improve the overall sound of the vehicle, giving it a more aggressive tone while contributing to better engine performance.
- Performance Mufflers: Upgrading to a performance muffler can improve exhaust flow and reduce back pressure while offering a more desirable sound profile. These mufflers are typically designed to enhance the sound of the engine without being excessively loud, providing a balance between performance and comfort.
- Stainless Steel Construction: Choosing exhaust components made from stainless steel ensures durability and resistance to corrosion. This longevity translates to consistent performance over time, making it a worthwhile investment for those who frequently use their 4.0 TJ in various conditions.
- Customized Exhaust Tips: While primarily aesthetic, upgraded exhaust tips can enhance the overall exhaust system appearance and improve exhaust flow slightly. Tailoring the size and shape of the tips can also help in achieving the desired sound characteristics, complementing the performance upgrades.
What Are the Most Popular Exhaust Brands for 4.0 TJ Owners?
The most popular exhaust brands for 4.0 TJ owners include:
- Flowmaster: Known for their aggressive sound and performance enhancement, Flowmaster exhaust systems are a favorite among TJ owners looking for a deep, throaty tone. Their designs often feature mandrel bends for improved exhaust flow, which can lead to increased horsepower and torque.
- Borla: Borla exhaust systems are recognized for their high-quality materials and performance engineering, providing a more refined sound while maximizing engine output. Their systems typically come with a lifetime warranty, making them a reliable choice for long-term durability and performance.
- MagnaFlow: MagnaFlow is celebrated for producing exhaust systems that balance sound, performance, and durability, offering a smooth, deep tone that enhances the driving experience. Their stainless steel construction ensures resistance to corrosion, making them suitable for various driving conditions.
- Pypes: Pypes exhaust systems are designed to deliver a unique sound and improved performance at a competitive price point. They often feature a modular design, allowing for easy installation and customization, which appeals to DIY enthusiasts.
- DynoMax: DynoMax offers exhaust systems that are engineered to enhance horsepower and torque while providing a mellow sound profile. Their systems are typically designed with a focus on easy installation and a good fit, making them an attractive option for those seeking a straightforward upgrade.
How Does Flowmaster Compare in Terms of Performance for the 4.0 TJ Exhaust?
| Aspect | Flowmaster | Other Options |
|---|---|---|
| Performance | Improved horsepower and torque; specifically tuned for the 4.0 TJ. | Varies by brand; some may offer similar performance gains but may not be as optimized. |
| Sound Quality | Deep, aggressive tone that enhances the driving experience. | Sound profiles can differ significantly; some may be louder or quieter. |
| Installation Ease | Designed for direct fit; generally easy to install with basic tools. | Installation complexity varies; some may require modifications or professional help. |
| Price | Typically ranges from $300 to $600. | Ranges widely; can be found from $200 to $700 depending on brand and features. |
| Durability | Constructed from high-quality materials for long-lasting performance. | Durability varies; some options may use lower quality materials affecting longevity. |
| Warranty | Offers a limited lifetime warranty. | Warranties vary by brand; some may offer limited warranties ranging from 1 to 5 years. |
What Makes Borla a Preferred Option Among 4.0 TJ Enthusiasts?
Borla is often regarded as a top choice for 4.0 TJ enthusiasts due to its superior performance, sound quality, and durability.
- Performance Gains: Borla exhaust systems are engineered to enhance engine efficiency and output, providing noticeable power gains for the 4.0 TJ.
- Distinctive Sound: The unique and aggressive sound profile of Borla exhausts appeals to many enthusiasts, offering a deep, throaty growl that enhances the driving experience.
- Quality Materials: Constructed from high-quality stainless steel, Borla exhaust systems are designed to resist rust and corrosion, ensuring longevity and reliability in various driving conditions.
- Easy Installation: Many Borla systems are designed for straightforward bolt-on installation, making it accessible for DIY enthusiasts and saving on professional installation costs.
- Variety of Options: Borla offers a range of exhaust configurations, including cat-back and axle-back systems, allowing customization to meet individual preferences and performance goals.
Performance Gains: Borla exhaust systems are engineered to enhance engine efficiency and output, providing noticeable power gains for the 4.0 TJ. With improved airflow characteristics, these systems help reduce back pressure, allowing the engine to breathe easier and perform better under various driving conditions.
Distinctive Sound: The unique and aggressive sound profile of Borla exhausts appeals to many enthusiasts, offering a deep, throaty growl that enhances the driving experience. This distinctive sound can be a significant factor for those looking to make their vehicle stand out on the road or trail.
Quality Materials: Constructed from high-quality stainless steel, Borla exhaust systems are designed to resist rust and corrosion, ensuring longevity and reliability in various driving conditions. This durability is essential for off-road enthusiasts who face harsh environments and require an exhaust that can withstand the elements.
Easy Installation: Many Borla systems are designed for straightforward bolt-on installation, making it accessible for DIY enthusiasts and saving on professional installation costs. This ease of installation allows users to quickly enhance their vehicle’s performance without extensive modifications.
Variety of Options: Borla offers a range of exhaust configurations, including cat-back and axle-back systems, allowing customization to meet individual preferences and performance goals. This variety ensures that 4.0 TJ owners can find the perfect system that matches their desired sound level and performance enhancements.
What Factors Influence Exhaust Sound Quality and Performance on a 4.0 TJ?
Several factors influence the exhaust sound quality and performance on a 4.0 TJ.
- Exhaust Material: The type of material used in the exhaust system can significantly affect sound quality and durability. Stainless steel is commonly favored for its resistance to corrosion and ability to produce a clear, aggressive tone, while mild steel may resonate differently but is often less durable.
- Exhaust Diameter: The diameter of the exhaust pipes impacts both sound and performance. Larger diameter pipes can enhance exhaust flow, leading to better performance and a deeper sound, but may also result in a drone at certain RPMs if not matched properly with the engine’s output.
- Muffler Design: The design of the muffler plays a crucial role in sound output. Performance mufflers, often straight-through designs, reduce back pressure and enhance horsepower while producing a louder, more aggressive sound. Conversely, stock mufflers tend to be more restrictive and quieter.
- Exhaust Configuration: The configuration, whether single or dual exhaust, affects both sound and performance characteristics. A dual exhaust system generally provides a more aggressive sound and improved flow, while a single exhaust can produce a distinct tone but may not perform as efficiently.
- Resonators: The inclusion or exclusion of resonators in the exhaust system can modify sound characteristics. Resonators can help eliminate unwanted frequencies, refining the exhaust note for a more pleasant sound, whereas their absence can lead to a louder and raspier tone.
- Heat Shields and Insulation: The presence of heat shields and insulation materials can influence the sound quality by reducing vibrations and unwanted resonance. Proper insulation helps maintain the desired sound profile and can prevent the exhaust from sounding harsh or tinny.
- Installation Quality: The quality of installation affects exhaust performance and sound. Proper alignment and secure fittings ensure that there are no leaks, which can lead to unwanted noise and reduced efficiency. A poorly installed system can produce rattles or vibrations that detract from the overall sound quality.
- Engine Tuning: The tuning of the engine itself can also play a role in how the exhaust sounds. A well-tuned engine optimizes performance and can enhance the exhaust note, creating a more balanced and enjoyable sound experience.
What Do Users Recommend About Their Experiences with Different Exhaust Systems for the 4.0 TJ?
When it comes to selecting an exhaust system for the 4.0 TJ, user experiences highlight several popular choices, each with unique benefits.
-
Borla: Users often praise the Borla exhaust for its deep, aggressive sound and improved performance. Many note enhanced horsepower and torque, particularly at higher RPMs.
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Flowmaster: This system is favored for its well-rounded performance and distinctive growl. Reviews frequently mention its ability to reduce back pressure and provide a noticeable boost in throttling response.
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MagnaFlow: Known for its stainless steel construction, MagnaFlow’s exhaust systems are recommended for durability. Customers appreciate the mellow tone at cruising speeds and a robust roar when accelerating.
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DynoMax: Users report satisfaction with the DynoMax exhaust’s excellent sound quality and installation ease. Its ability to enhance flow while minimizing raspiness is often highlighted.
In addition to these brands, many users advise considering personal driving style and the type of driving—off-roading versus on-road—when choosing an exhaust to align with individual performance needs.
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