Stainless Valved Catback Exhaust System for Audi B9 S4 S5

The Audi B9 S4 and S5, powered by the EA839 3.0L V6, offer strong performance from the factory—but the stock exhaust limits the engine’s true sound and character. The STRATEC Valved Exhaust System unlocks a more aggressive, performance-driven exhaust tone while retaining refined, OEM-like manners when desired.

Engineered as a complete, one-piece exhaust system, this setup runs from the downpipe connection to the exhaust tips, eliminating the need to mix components from multiple suppliers. The result is consistent sound quality, proper fitment, and seamless performance.

With valves open, expect a bold, motorsport-inspired exhaust note with pronounced overrun crackles. With valves closed, the system returns to a quiet, refined tone suitable for daily driving—without unwanted drone when paired with the factory downpipe.

Why It Works

• Complete One-Piece System: No mixing of axle-backs or resonators

• Electronic Valve Control: Instantly switch between aggressive and refined sound

• Mandrel-Bent Design: Optimized exhaust flow for improved throttle response and power

Sound & Control

• Valves Open: Aggressive tone with strong midrange and sharp overrun crackles

• Valves Closed: Quiet, refined, and OEM-like for daily driving

• No Drone: When used with the factory downpipe

Construction & Details

• Material: Full T304 stainless steel construction

• Weight Savings: Approx. 16.4 lbs lighter than factory exhaust

• Craftsmanship: Precision TIG welding and smooth mandrel bends

• Exhaust Tips: Includes premium tips for a clean, performance-oriented finish

Vehicle Fitment

• 2017–2024 Audi S4 (B9)

• 2018–2024 Audi S5 (B9)