Best Infiniti G37 Cat-Back Exhaust Systems (2008-2013)

A quality Infiniti G37 cat-back exhaust is the single best-sounding bolt-on you can add to the 3.7L VQ37VHR V6. From the factory, the 2008–2013 G37 makes 330 hp at 7,000 rpm and 270 lb-ft at 5,200 rpm (348 hp in the 2012–2013 IPL), and that free-revving V6 is begging to breathe. Swapping the restrictive OEM mufflers for a mandrel-bent stainless cat-back wakes up the top end, drops weight, and unlocks the signature VQ growl. At NLP Performance in Tampa, FL, the G37 and its Q60 sibling are among the most common cars our customers exhaust-shop for — so we pulled our five best-selling systems together and compared material, tips, tone, and price to help you pick the right one.

How Much Power Does a G37 Cat-Back Exhaust Add?

A cat-back exhaust on the Infiniti G37 typically adds 8–12 horsepower and a similar bump in torque, with aFe publishing dyno gains of up to +12 hp and +9 lb-ft for its Takeda system. Because a cat-back replaces everything after the catalytic converters — the mid-pipes, resonators, and mufflers — it reduces backpressure without touching emissions equipment, so it stays 50-state street-legal. On a naturally aspirated VQ37VHR the gains land mostly in the mid-to-upper rev range, exactly where you feel the car pull toward its 7,500-rpm redline. Pair the cat-back with a cold-air intake and a tune and the combined package can push closer to 20–25 wheel horsepower.

The 5 Best Infiniti G37 Cat-Back Exhaust Systems

Every kit below is confirmed to fit the 3.7L VQ37VHR G37 (and, where noted, the 2014–2015 Q60 that shares the platform). We ranked them on sound quality, build material, fit, and value. Coupe and sedan share most hardware, but tip and muffler routing differ — always match the kit to your body style.

1. aFe Takeda 2-1/2 in. 304 SS Cat-Back — Best Overall

The Takeda system is our top pick because it nails the balance every G37 owner wants: a deep, aggressive note under throttle with minimal highway drone, backed by real dyno numbers. aFe builds it from mandrel-bent 2-1/2 in. 304 stainless with fully welded 4 in. black double-wall tips, and publishes gains of up to +12 hp and +9 lb-ft. It fits both the coupe and sedan (and the Q60), carries a limited lifetime warranty, and around $1,850 lands right in the middle of the pack. A polished-tip version (49-36103-P) is available if black tips aren’t your look.

2. MagnaFlow 16820 Street Series Cat-Back — Best Refined Street Tone

If you want more presence than stock but still a mature, resonant tone, the MagnaFlow 16820 is the one. It uses fast-flowing 2.5 in. mandrel-bent piping and three straight-through mufflers feeding a dual split rear exit with 4.5 in. polished double-wall angle-cut tips. The result is MagnaFlow’s signature deep note — aggressive when you get on it, comfortable at cruise, and quiet enough that the cabin stays livable. At around $1,650 it’s the value pick among the coupe systems and carries a lifetime warranty. It also covers the 2014–2015 Q60 3.7L.

3. HKS Hi-Power Dual Titanium-Tip Cat-Back — Loudest JDM Character

For owners chasing the loudest, most authentic JDM soundtrack, the HKS Hi-Power is the halo pick at around $2,000. It’s built from SUS304 stainless with the legendary Hi-Power muffler design and dual burnt-titanium tips that look the part. Expect the most aggressive tone of this group — a hard-edged rasp at wide-open throttle that VQ fans love, though it’s the least commuter-friendly here. It is a coupe-specific system and, as the priciest option, it’s aimed at the enthusiast who wants the HKS badge and sound above all else.

4. Injen 76mm Stainless Cat-Back with Titanium Tips — Best for the Coupe Look

Injen’s coupe-specific system uses large 76mm (3 in.) stainless mainline piping and burnt-titanium tips for a purposeful, race-inspired look and a strong, aggressive tone. The larger diameter favors upper-rpm flow, so it’s a good match for owners who plan to add an intake and tune down the road. At around $1,700 with a limited lifetime warranty, it slots between the value MagnaFlow and the premium HKS. Note it’s built for the G37 (and IPL) coupe specifically — sedan owners should choose the aFe or a sedan-fit Invidia.

5. Invidia Gemini Rolled Titanium-Tip Cat-Back — Best Value

The Invidia Gemini is the smart-money buy right now — marked down from $2,232.72 to around $1,475, it’s the lowest entry price in this guide for a full titanium-tip stainless cat-back. The rolled dual titanium tips give the coupe a factory-plus look, and the tone lands in aggressive-but-liveable territory, a notch below the HKS. It’s a longtime enthusiast favorite for the G37/370Z VQ platform. The trade-off versus the top picks is a shorter one-year warranty, but for the money the value is hard to beat.

Infiniti G37 Cat-Back Exhaust Comparison

Here is how the five systems stack up on build material, tip finish, and tone. All are mandrel-bent stainless cat-backs for the 3.7L VQ37VHR; prices update live to current NLP Performance pricing.

Coupe vs. Sedan: Does Body Style Change the Fitment?

Yes — the G37 coupe and sedan use different rear sections, so you must buy a kit that matches your body style. Most of the premium systems here (HKS, Injen, and the Invidia Gemini) are engineered for the two-door coupe with dual center or split-rear exits. The aFe Takeda 49-36103 covers both coupe and sedan (plus the 2014–2015 Q60), while MagnaFlow’s 16820 is the coupe-and-Q60 fit. Sedan owners have great options too — look for a sedan-specific Invidia Q300 or the sedan aFe listing. When in doubt, check your VIN or ask our Tampa team to confirm before you order.

Do You Need Headers or a Tune With a Cat-Back?

No — a cat-back exhaust is a bolt-on that requires no tune and keeps your catalytic converters, so it stays emissions-legal and check-engine-light-free on the G37. That’s exactly why it’s the most popular first mod. If you later add high-flow test pipes or long-tube headers, a tune is recommended to manage air-fuel ratios and clear any downstream O2 codes. For most owners, the smart path is cat-back first for sound and a modest power bump, then intake, then headers and a tune once you’re chasing bigger numbers.

What to Look For in a G37 Cat-Back Exhaust

The three things that matter most in a G37 cat-back are material, muffler design, and tip style. Every system in this guide is built from mandrel-bent 304 stainless steel — the grade you want, because it resists rust and heat discoloration far better than aluminized or 409 stainless, which is why brands like aFe, MagnaFlow, and Injen back theirs with limited-lifetime or lifetime warranties. Muffler design sets the tone: straight-through, packed mufflers (MagnaFlow, aFe) flow freely while taming drone, whereas the HKS Hi-Power chamber design trades some cabin comfort for that hard-edged race rasp. Piping diameter is the last lever — 2.5 in. is ideal for a naturally aspirated VQ37 street car, while Injen’s 76mm (3 in.) mainline favors upper-rpm flow for owners planning intake and tuning. Finally, tip finish (polished, black, or burnt titanium) is pure aesthetics, so pick the look you want under the rear valance.