Audi S4 S5 B9 Catless Downpipe 2017

Audi S4/S5 B9 Catless Downpipe

Unlock the True Potential of the B9
Does your 2017 or newer Audi S4/S5 B9 feel underpowered due to factory emission-restrictive hardware? Our high-flow cat-back exhaust is the ultimate upgrade for enthusiasts seeking maximum power, an aggressive sound, and unrestricted performance from the 3.0T V6 engine.
As a direct bolt-on replacement for the stock catalytic converter assembly, this exhaust system eliminates the restrictive stock catalytic converter setup, unleashing the airflow your engine has always craved.

Key Features
Premium Stainless Steel: Crafted from high-grade mirror-polished T304 stainless steel, offering unmatched durability, corrosion resistance, and a pristine under-the-hood appearance that lasts for years.
Precision-Bent Y-Pipe Design: A precision-engineered 2-into-1 merging collector ensures smooth, unobstructed exhaust flow, eliminating the power-robbing bottlenecks found in the stock system.
Racing-Grade Welding: TIG-welded seams guarantee leak-free performance under high temperatures and boost pressure, while reinforced joints withstand the demands of aggressive driving.
Direct Bolt-On Installation: Designed specifically for 2017 and newer Audi S4/S5 B9 models (3.0T V6). No cutting, no modifications—utilizes OEM mounting points and hardware for installation in minutes.
O2 Sensor Interface: An integrated interface ensures proper sensor installation (for off-road use only; please check local emissions regulations before installation).
Aggressive Sound Upgrade: Eliminates the muffled, subdued tone of the stock system, delivering a deep, rich exhaust note without annoying high-pitched squeals at high RPMs.

Performance Benefits
Immediate Power and Torque Gains: Delivers 15–25 horsepower and 20–30 lb-ft of torque; results are even more pronounced when paired with custom tuning or an ECU flash.
Reduced Turbo Backpressure: Enables faster turbo spool-up, eliminates lag, and provides a responsive throttle feel across the entire RPM range.
Lower Exhaust Temperatures: Improved airflow reduces heat buildup under the hood, helping to prevent thermal fade during aggressive driving or track events.
Enhanced Exhaust Sound: The free-flowing design produces a deep rumble at idle and a smooth, aggressive roar at full throttle, without the harsh buzzing typical of cheap aftermarket exhausts.

Compatibility and Notes
Compatible Vehicles: 2017 and newer Audi S4 (B9)/S5 (B9) with 3.0T V6 engines. Installation: Direct bolt-on replacement; no permanent modifications required.

Important Note: This is a catalytic converter-free part intended for off-road use only. It is not designed for use on public roads subject to emissions regulations. Please check local regulations before purchasing and installing.

Built by Enthusiasts, for Enthusiasts

At Fu Power, we design every exhaust component with a single goal in mind: to deliver reliable, track-level performance that matches the spirit of your Audi. Our B9 downpipe has been rigorously tested to withstand the high boost and extreme temperatures of the 3.0T engine, giving you confidence behind the wheel.

Ready to free your S4/S5 from factory limitations? Upgrade to our catalytic converter-free downpipe today and experience the raw sound and power your B9 was meant to deliver.