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Upgrading to a cat-back exhaust system can change how your Infiniti Q50 sounds and performs on the road. The right system balances airflow, durability, and noise to match daily driving or spirited use. This guide covers seven shortlisted cat-back exhaust systems chosen for their build quality, expected sound characteristics, and fitment reliability. We evaluated materials, acoustic tuning, and installation considerations to help you find a system that meets your goals. Read on for a concise rundown of what to expect and which features matter most.
Looking for other parts? See all Infiniti Q50 parts & accessories.
Top Picks at a Glance
| Best Reviewed A top-rated pick with lots of positive feedback | MBRP S5085AL 2.5" Cat-Back Dual Rear Exhaust System (Aluminized Steel) |  |
| Most Popular A crowd favorite that many people choose with confidence | Diamond Eye K4234A Cat-Back Exhaust System |  |
| Best Quality Built to a higher standard if you want something more solid | Flowmaster American Thunder Cat-Back Exhaust System |  |
| Best Budget The cheapest option that still gets the job done reliably | MBRP S5200AL 3" Cat-Back Exhaust System (Aluminized Steel) |  |
| Most Sold A high-volume bestseller chosen again and again | Invidia Q300 Cat-Back Exhaust System with Stainless Steel Tip for Infiniti G35 4‑Door |  |
| Best Value for Money The sweet spot between price and what you get | MBRP S5236AL 3" Aluminized Steel Single Side Exit Cat-Back Exhaust System |  |
| Best Overall The best all-around choice for most situations | MBRP S7275BLK 3" Cat-Back Race Exhaust System (Black Coated) |  |
1. MBRP S5085AL 2.5" Cat-Back Dual Rear Exhaust System (Aluminized Steel)
| Material | Aluminized steel |
|---|---|
| Tubing | Mandrel-bent 2.5" and 3" tubing |
| System type | Cat-back, dual rear exhaust |
| Compatibility note | Uses factory exhaust bezels |
The MBRP S5085AL is a cat-back exhaust system built from aluminized steel that replaces the factory rear section to improve exhaust flow and sound. It is typically used to upgrade a Q50 for a fuller, throatier tone and slightly better flow without extensive modifications. Notable features include mandrel-bent tubing and fully sealed seams intended to resist rust compared with cheaper kits, plus compatibility with factory exhaust bezels for a straightforward cosmetic fit. The system advertises a significant flow increase and is positioned as a practical, installer-series upgrade that mirrors MBRP’s higher-end specs while keeping costs down. In practice this yields a noticeable sound change on acceleration and a modest performance benefit under load. Limitations are the aluminized steel construction, which is less corrosion-resistant than stainless options over many years, and the potential need for minor trimming or clamps during installation depending on exact Q50 rear geometry. Fitment and tone will vary by Q50 model and existing exhaust layout, so expect a hands-on install or professional fitment for best results.
Best for: Reliability-focused buyers who want a durable, no-frills sound and flow upgrade for their Q50 while prioritizing a product built to resist common seam rust issues.
Less Ideal for: Buyers seeking the highest long-term corrosion resistance or a premium show-quality finish should consider stainless systems or higher-end models instead.
- Mandrel-bent tubing for smoother exhaust flow and reduced restriction
- Fully sealed seams to reduce early rust-through compared with some budget systems
- Designed to use factory exhaust bezels for a cleaner fit and appearance
- Advertised flow improvement that can translate to better throttle response under load
- Aluminized steel is less corrosion-resistant than stainless steel over long-term use
- May require trimming or adjustment for exact fit on some vehicle rear layouts
Verdict A practical, reliability-minded cat-back that gives the Q50 a louder, freer-flowing exhaust with a cost-conscious aluminized steel build.
2. Diamond Eye K4234A Cat-Back Exhaust System
| Manufacturer | Diamond Eye |
|---|---|
| Item model number | K4234A |
| Item Weight | 57 pounds |
| Product Dimensions | 52 x 13 x 21 inches |
This Diamond Eye cat-back system replaces the rear section of the factory exhaust to improve flow and produce a deeper, more aggressive tone. It uses large mandrel-bent tubing and a Fasttrak-style straight-through perforated-core muffler to reduce backpressure and create a fuller low-end rumble while aiming to avoid excessive drone. Installation is intended as a direct bolt-on to factory connection points and includes clamps and mounting hardware, though some trimming or bracket adjustment may be necessary to achieve perfect fitment. The kit is typically used when pairing with other bolt-on upgrades like an intake or tuner to unlock additional performance gains. Practical benefits include clearer exhaust flow for modest horsepower and torque improvements and a noticeably richer sound without going to a straight pipe. Limitations are that the kit can require modification for certain chassis or clearance situations and fitment was not explicitly specified for Infiniti Q50, so professional fit verification is recommended before purchase.
Best for: Convenience-driven buyers who want a simple bolt-on way to improve exhaust sound and flow while minimizing time in the shop and coordinating with other bolt-on upgrades.
Less Ideal for: Drivers seeking a guaranteed, vehicle-specific kit for the Infiniti Q50 or those who want a silent, stock-like exhaust should look for systems listed specifically for their model or a custom solution.
- Mandrel-bent large-diameter piping for improved exhaust flow
- Performance-tuned straight-through muffler that produces a deep tone with reduced rasp
- Ships with clamps and mounting hardware for a bolt-on installation
- Works with other bolt-on upgrades like intake or tuner to realize further gains
- May require cutting, hanger adjustment, or welding to fit certain vehicle layouts
- Fitment to the Infiniti Q50 is not guaranteed and may need professional verification
Verdict A budget-friendly bolt-on cat-back that delivers deeper tone and better flow but may need minor modifications and fit verification for model-specific installation.
3. Flowmaster American Thunder Cat-Back Exhaust System
| Connects After | Factory catalytic converter |
|---|---|
| Tubing | Mandrel-bent 16 gauge stainless steel |
| Includes | Hangers and hardware |
| Muffler Series | 50-series (moderate tone) |
This Flowmaster American Thunder cat-back system replaces the factory rear exhaust section and is built from mandrel-bent 16 gauge stainless tubing with hangers and hardware included for installation. It is designed to connect after the catalytic converter and uses the factory hanger locations, so installation is straightforward for a shop familiar with cat-back swaps. The kit comes with a moderate exterior tone thanks to the 50-series muffler and aims to add a deeper, more aggressive sound without excessive drone. Practical benefits include robust stainless construction for longer life and included hardware to avoid sourcing extra parts. Limitations are that fitment is specific to the original application and may require trimming or welding on non-matching chassis, and some users report tip alignment and clamp tightness that can need adjustment or welding. Expect improved sound and a durable system, but plan on professional fitment or basic fabrication for perfect results on a different vehicle.
Best for: Performance-oriented buyers who prioritize durable, factory-quality exhaust hardware and a deeper but controlled exhaust tone and are comfortable having a shop adapt fitment as needed.
Less Ideal for: Buyers seeking a vehicle-specific, bolt-on performance tune for an Infiniti Q50 without modification or those who want an extremely loud or track-focused exhaust voice.
- Mandrel-bent 16 gauge stainless steel tubing for smoother flow and corrosion resistance
- Includes hangers and hardware to simplify installation
- Designed to use factory hanger locations for a more direct fit
- Moderate but aggressive exterior tone from the 50-series muffler
- Original fitment targets trucks and may require trimming or welding for other vehicles
- Clamps and exhaust tips may need adjustment or welding for secure alignment
- Not tuned for vehicle-specific performance gains beyond sound improvement
Verdict A well-built stainless cat-back that delivers a deeper, controlled tone and long-term durability but may need fitment work and is not a vehicle-specific performance tune for the Infiniti Q50.
4. MBRP S5200AL 3" Cat-Back Exhaust System (Aluminized Steel)
| Installation Type | Clamp-On |
|---|---|
| Finish Type | Aluminized |
| Manufacturer | MBRP |
| Pipe Diameter | 3" |
The MBRP S5200AL cat-back is a clamp-on exhaust system built from heavy aluminized steel to deliver improved torque, horsepower, and a deeper exhaust note without a major cost jump. It installs using common hand tools and clamps to factory hangers so a competent DIYer or a shop can complete the job without welding. The system is tuned for a throaty but not extreme tone and is intended to speed the evacuation of hot exhaust gases for cooler, more efficient engine operation. Practical advantages include relatively easy installation, a mirror-polished tip for a finished look, and corrosion-resistant aluminized seams compared with thin alternatives. Downsides to expect are the potential for mid‑highway drone at certain RPMs and that aluminized steel will not be as long-lived or corrosion-resistant as stainless options. Some buyers report trimming or minor adjustments are needed for perfect fitment, so plan on basic modification time during installation.
Best for: Budget-conscious owners who want a cost-effective way to add a deeper exhaust note and modest performance gains while keeping installation straightforward.
Less Ideal for: Drivers seeking the longest-term corrosion resistance or a completely drone-free, refined touring sound should consider higher-end stainless options or different muffler choices.
- Clamp-on, bolt-on design that installs with common hand tools
- Heavy gauge aluminized steel construction with coated seams for improved corrosion resistance versus thin aluminized systems
- Tuned for a rich, mellow but not overly loud exhaust note
- Includes polished tip for a finished appearance
- Aluminized steel is less durable and corrosion-resistant than stainless steel
- Some users report a noticeable drone at highway speeds
- May require cutting or minor trimming for exact fitment during installation
Verdict A wallet-friendly cat-back that gives stronger sound and modest performance gains with easy clamp-on installation but sacrifices some longevity compared with stainless systems.
5. Invidia Q300 Cat-Back Exhaust System with Stainless Steel Tip for Infiniti G35 4‑Door
| Tip size | 110 millimeter |
|---|---|
| Piping diameter | 60 millimeter |
This Invidia Q300 cat-back replaces the stock rear exhaust on compatible Infiniti models and is built to provide a quieter, refined sporty tone while improving exhaust flow. It uses polished SUS304 stainless piping with mandrel bends, robot TIG welds, CNC flanges and double-wall polished tips for corrosion resistance and a factory-quality finish. The muffler layout and continuous piping are intended to reduce back pressure, which in practical use can give a modest bump in throttle response and a richer sound above cruising revs rather than an aggressive rasp. Installation is typical of cat-back systems and can be done by a competent DIYer or a shop; some buyers report small fitment adjustments may be needed. The sound profile favors a subdued, refined character inside the cabin while audible at higher RPMs, so it suits owners who want improved tone without excessive noise. It is not aimed at those wanting a loud, track-style exhaust or who need explicit fitment instructions in the box.
Best for: Risk-averse mainstream buyers who prioritize a reliable, factory-quality upgrade that improves exhaust tone and drivability without drawing attention.
Less Ideal for: Performance enthusiasts seeking a loud, race-oriented exhaust or buyers who need out-of-the-box step-by-step installation guidance.
- SUS304 stainless steel piping and polished tips resist corrosion and clean up well.
- Mandrel-bent piping and CNC flanges preserve flow for potential horsepower and torque gains.
- Factory-style sound tuning yields a deeper tone without being overly loud.
- Robot TIG welding and machined components improve durability and fit quality.
- Not as loud as some aftermarket performance systems, so it may not satisfy those seeking an aggressive exhaust note.
- Box does not include installation instructions which can complicate DIY install for less experienced users.
Verdict A durable, factory-tuned cat-back for Infiniti owners who want a deeper, refined exhaust tone and modest performance gains without aggressive noise.
6. MBRP S5236AL 3" Aluminized Steel Single Side Exit Cat-Back Exhaust System
| Pipe diameter | 3 inches |
|---|---|
| Material | Aluminized steel |
| Tip material | T304 |
| Construction gauge | 16 gauge |
This MBRP cat-back is a budget-friendly alternative to higher-end stainless systems that aims to deliver the same power and sound characteristics as the brand's Pro Series. It replaces the factory rear section with 3-inch piping and mirror-polished T304 tips to produce a richer, fuller exhaust note and modest torque and horsepower gains. Typical use is direct replacement and street driving on an Infiniti Q50 where owners want improved throttle response and a more engaging sound without a large investment. Notable features include heavy 16-gauge aluminized steel construction, aluminum-silica seam protection to resist rust, and straightforward install with common hand tools. Practical benefits are lower cost versus stainless, a robust protective coating on vulnerable seams, and relatively simple installation for a competent mechanic. Limitations are that aluminized steel is less corrosion-resistant long term than stainless, there have been occasional reports of shipping damage to parts, and fitment or finish may not match factory-quality stainless systems for owners seeking maximum longevity or showroom appearance.
Best for: Practical optimizer buyers who want noticeable power and sound improvements on an Infiniti Q50 without paying for premium stainless systems and who prioritize value and sensible durability.
Less Ideal for: Owners seeking the longest-term corrosion resistance or showroom-perfect finish should consider a stainless steel system instead.
- Matches Pro Series performance goals with increased torque and horsepower
- 16-gauge aluminized steel with aluminum-silica seam coating reduces early rust at seams
- Mirror-polished T304 tips improve appearance and provide a richer exhaust tone
- Designed for installation with common hand tools for relatively simple fitment
- Aluminized steel will not resist corrosion as long as stainless steel alternatives
- Some customers have received damaged pieces during shipping requiring repair
Verdict A cost-conscious cat-back that delivers Pro Series-like sound and gains using heavy aluminized steel, best for Q50 owners who want value over stainless longevity.
7. MBRP S7275BLK 3" Cat-Back Race Exhaust System (Black Coated)
| Exhaust type | Cat-back system |
|---|---|
| Tubing diameter | 3 inches |
| Finish | Black high-heat coating |
| Fitment note | Bolt-on using factory hangers |
The MBRP S7275BLK is a 3-inch cat-back race exhaust marketed as a direct-fit bolt-on system that replaces the factory rear section and delivers a deeper, more aggressive sound while improving exhaust flow. For Infiniti Q50 owners looking to add character and a small performance gain the system installs using factory hangers and included clamps, so professional or experienced DIY installation is straightforward. Notable features include mandrel-bent tubing for smoother flow, a race-tuned muffler profile for a low, muscular tone, and a high-heat black coat that resists corrosion and keeps a stealth look. Practical benefits are stronger throttle sound and potentially reduced exhaust temperatures that can help drivability when paired with other bolt-on mods. Limitations to consider are mixed fitment and build-quality reports from other users on alignment and tip fitment, and the race version can produce more low-speed growl and some drone under certain conditions compared with touring-style systems. If you want a bold, factory-replacement-style upgrade with a black finish, this system delivers; if you prioritize perfect tip alignment or near-silent cruising, check fitment carefully before purchase.
Best for: Balanced all-round buyers who want a pronounced, muscular exhaust note and an easy bolt-on performance upgrade that keeps a stealthy look on their Infiniti Q50.
Less Ideal for: Drivers who prioritize near-silent daily cruising, perfectly finished cosmetic fitment, or who want a premium stainless finish should consider quieter or higher-end alternatives.
- Mandrel-bent 3" tubing for improved exhaust flow and reduced backpressure
- Bolt-on design using factory hangers and included clamps for straightforward installation
- Race-tuned muffler produces a deep, aggressive tone that enhances throttle feel
- High-heat black coating resists corrosion and maintains a stealth appearance
- Some users report fitment and alignment issues with tips and hangers on certain vehicles
- Build quality varies across units with occasional imperfect welds noted
Verdict A bold-sounding, bolt-on cat-back that gives the Infiniti Q50 a muscular tone and improved flow but requires attention to fitment and finish.
Choosing the Right Infiniti Q50 Cat-back Exhaust System: Key Factors to Consider
Material and Corrosion Resistance
The choice of material affects lifespan and maintenance. Stainless steel alloys resist road salt and moisture better than mild steel, reducing the chance of rust and premature failure.
Weld quality and flange construction also matter because weak joints accelerate wear. Consider corrosion-resistant coatings or higher-grade stainless if you plan to keep the vehicle long term or drive in wet climates.
Pipe Diameter and Flow Design
Pipe diameter and internal shaping influence exhaust flow and backpressure. Larger diameters can support higher airflow and potential power gains at higher RPMs, while too-large piping can reduce low-end response.
The internal flow design, such as mandrel bends and smooth transitions, helps maintain consistent velocity and reduces turbulence. Match the system's flow characteristics to your driving habits to preserve desirable throttle response.
Muffler and Resonator Configuration
Mufflers and resonators control the tone, volume, and resonance inside the cabin. More aggressive muffler designs create a louder, sportier exhaust note but can also introduce drone at cruising speeds.
Dual-chamber or tuned resonators can smooth sound and reduce unpleasant frequencies. Think about whether you want a track-oriented growl or a refined street tone when choosing the configuration.
Fitment and Installation Ease
A system that fits precisely cuts installation time and reduces the need for modifications. Look for kits that include gaskets, hangers, and hardware sized for the Infiniti Q50 for a straightforward replacement.
Clear instructions and exact flange specifications help prevent leaks and alignment issues. If you plan to install the system yourself, factor in the complexity of access under the vehicle and whether special tools are required.
Acoustic Goals and Noise Regulations
Decide on the target sound level and check local noise ordinances. Some systems are tuned to be aggressive under load but quiet at idle, while others remain loud across the rev range.
Balancing legal considerations with personal preference helps avoid fines and neighbor complaints. Consider whether a resonated option or an exhaust with modular components better meets both street and occasional spirited driving needs.
Compatibility With Sensors and Emissions Hardware
Ensure the aftermarket system preserves the placement of oxygen sensors and any emissions-related components to maintain proper engine management. Incorrect sensor positioning can lead to check-engine lights or altered fueling.
Kits that retain stock mounting points and provide provisions for sensors minimize the risk of drivability issues. If emissions legality matters in your area, confirm the system's compliance before purchase.
FAQ
Will a cat-back exhaust system increase power on my Infiniti Q50?
A cat-back system can improve exhaust flow, which may yield modest gains in throttle response and peak power depending on the existing restrictions. Gains are usually most noticeable when paired with other engine or intake modifications. Results depend on pipe diameter, flow design, and how well the system matches the engine's characteristics.
How difficult is catback exhaust installation on an Infiniti Q50?
Installation difficulty varies by kit but many cat-back systems are designed for bolt-on replacement using existing hangers and flanges. Basic mechanical skills and common tools are often sufficient, though some situations may require lifts or penetrating oil for rusted bolts. Professional installation is recommended if you lack experience or access to proper equipment.
Will the new exhaust make cabin drone worse?
Some aggressive systems can introduce drone at certain cruise RPMs, especially if they eliminate resonators or use straight-through mufflers. Choosing a system with tuned resonators or selecting muffler designs that target mid and high frequencies can reduce unpleasant cabin resonance. Expect a tradeoff between loudness under load and comfort at highway speeds.
Is stainless steel worth the extra weight for a cat-back exhaust?
Stainless steel typically costs more but offers better long-term corrosion resistance, which can be valuable in humid or salted-road regions. The weight difference is usually small compared with durability benefits. If longevity and low maintenance are priorities, stainless steel is a sensible choice.
Do I need to worry about emissions compliance with a cat-back system?
Cat-back systems generally replace components downstream of the catalytic converter and so often do not affect core emissions controls. However, local regulations vary and some areas have strict noise or modification rules. Confirm that the chosen system maintains proper sensor locations and meets any regional requirements before installing.
How We Chose the Best Infiniti Q50 Cat-back Exhaust System
We selected products that specifically fit the Infiniti Q50 and focused on attributes that matter most for this vehicle. Key evaluation criteria included build material and corrosion resistance, which affect longevity; pipe diameter and internal flow design, which influence power delivery and throttle response; muffler and resonator configuration, which determine sound character and cabin resonance; fitment accuracy and mounting hardware, which reduce installation headaches; and compatibility with stock sensors and emissions components to maintain proper operation. We prioritized systems with clear specifications and installation documentation. Units lacking detailed fitment information or that require unspecified modifications were excluded. We did not consider kits intended for other vehicle models or systems that only offer partial replacement without a full cat-back configuration.
Our full evaluation process is outlined in our review methodology.
Conclusion
Choosing the right Infiniti Q50 cat-back exhaust system means balancing sound, durability, and installation practicality. Prioritize material quality and fitment accuracy if you want long service life and hassle-free installation. Decide first whether your priority is a louder, track-focused tone or a refined street sound, then match pipe diameter and muffler configuration to that goal. Keep sensor compatibility and noise regulations in mind to avoid drivability issues and legal headaches.
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