Flashark Catless Test Pipes for 2008–2013 Infiniti G37/2014–2018 Q50 & 2009–2018 Nissan 370Z 3.7L V6

Free Up Your VQ37VHR Exhaust Flow

These Flashark catless test pipes are designed for selected 2008–2013 Infiniti G37, 2014–2018 Infiniti Q50, and 2009–2018 Nissan 370Z models with the 3.7L V6. They replace the restrictive factory catalytic-converter section with a freer-flowing 2.5-inch exhaust path for a sharper throttle feel and a more aggressive VQ exhaust note.

Many enthusiasts call this upgrade a “downpipe,” but on these naturally aspirated 3.7L V6 applications, the accurate term is catless test pipes. This kit is built for owners who want to reduce front-exhaust restriction without custom fabrication.

Built for Performance Exhaust Builds

• 2.5-Inch Inlet & Outlet: Free-flowing pipe design to support improved exhaust movement.
• Stainless Steel: Built to handle heat cycles, vibration, and corrosion exposure.
• Mandrel-Bent Tubing: Helps maintain a consistent internal diameter through each bend.
• TIG-Welded Joints: Durable weld construction for high-heat exhaust environments.
• CNC-Machined Flanges: Designed for accurate mounting surfaces and dependable sealing.
• Pre-Welded O2 Sensor Bungs: Allow installation of the factory oxygen sensors.
• Hardware & Gaskets Included: Includes the required installation hardware shown in the product images.

What to Expect After Installation

Catless test pipes can make your 3.7L V6 sound louder, sharper, and more aggressive—especially at higher RPM. The final sound level, rasp, cabin drone, and exhaust odor will depend on the rest of your setup, including the Y-pipe, cat-back exhaust, headers, and tune.

A tune is not required for physical installation, but it is recommended for modified vehicles that want to optimize their overall setup. Because this kit removes the factory catalytic converters, a check engine light may occur.

Before You Order

• Confirm the engine: Fits 3.7L V6 applications only.
• Do not order for 2.0T or 3.0T models: These use a different exhaust layout and are not compatible.
• Off-road/competition use only: This catless kit removes factory emissions equipment and may not be legal for street use or emissions-controlled vehicles.

(You will get exactly as shown in the picture above)

What This Test Pipe Kit Does

The factory catalytic converters help control emissions, but they also create restriction in the front exhaust section. Replacing them with catless test pipes gives exhaust gases a more direct path out of the engine, which can improve throttle response, increase exhaust volume, and support stronger power gains when the rest of the setup is matched well.

Performance Gain You Can Expect

On a mostly stock G37 or 370Z, a realistic gain from catless test pipes is usually around 8-15 HP. With a freer-flowing Y-pipe or cat-back exhaust and a proper ECU tune, the front exhaust upgrade can support about 10-20 HP depending on the car, fuel, tune quality, and supporting modifications.

The biggest change is not always peak horsepower. Many owners notice quicker revving, stronger mid-range response, and a much more open exhaust tone. A tune is not always required just to physically drive the car, but it is recommended if you want cleaner fueling, better drivability, and fewer CEL-related issues on an off-road setup.

Sound, Rasp, and Daily Driving Feel

These are non-resonated catless test pipes, so they will make the car louder than stock catalytic converters. With a factory-style or moderate cat-back, the tone is usually sharper and more aggressive. With a single-exit exhaust, muffler delete, or very open Y-pipe, expect more rasp, smell, and possible drone around cruising mandrel bends All-in-One Kits & Recommended Upgrades

Often, after purchasing the 2008-2018 Nissan 370z Infiniti G37 Z34 Downpipe Exhaust, customers will also purchase other items. Come on, check out Flashark's all-in-one kits and modify your car to your heart's content!

Complete Your Build: Maximize your exhaust flow and complete your system upgrade by pairing these downpipes with our 3-Inch Single Tip Cat-Back Exhaust for 2009-2020 Nissan 370Z.

Test Piper Restrictions Catalytic Converters

Factory catalytic converters are built for emissions control and quieter operation. Flashark catless test pipes are built for off-road exhaust flow and a more aggressive sound. The greater choice depends on how you use the car, and your matched build must meet local emissions requirements.

• Factory catalytic converters: Quieter, emissions-focused, and better for stree8- 15mpliance, but more restrictive when you are building an off-road performance exhaust setup.
• Flashark catless test pipes:10- 20r-flowing 2.5-inch stainless pipes that replace the factory catalytic converters for off-road and track use. They deliver a louder tone, stronger exhaust flow, and a sharper VQ sound.

Tuned vs Untuned Setup

These catless test pipes can be installed on a Cobra G37 or 370Z without an immediate tune, but tuning is recommended for the cleanest result. Without tuning, many owners still notice a sharper throttle feel and a louder exhaust note, but a Check Engine Light is possible because the factory catalytic converters are removed.

• Without a tune: Expect a louder tone, quicker rev feel, and possible CEL depending on the rear O2 sensor readings.
• With a proper tune: The car can take better advantage of the freer-flowing exhaust, with smoother fueling, stronger mid-range response, and better overall drivability.
• Power range: A realistic gain is about 8-15 HP with a basic bolt-on setup, or about 10-20 HP with racing exhaust upgrades and tuning.

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