Cat-back Milltek Audi S4 B9, S5 F5 - ECE Homologated - With primary muffler - Quad Jet-100 Carbon tips - with sport diff

Milltek Sport exhaust system for Audi S4 B9 / S5 F5

Replacing the original system with a Milltek Sport exhaust brings back the character that the factory setup muffles on your Audi S4 B9 / S5 F5: a rounder tone at idle that opens up cleanly through the rev range, without gimmicks.

Technical specifications

• Milltek part number: SSXAU721
• Part type: Exhaust system
• Configuration: with valves
• Detail: ECE homologated - with primary muffler - quad Jet-100 carbon tips
• Pipe diameter: 63.5 mm
• Outlets: 4 Jet outlets, 102 mm
• Tip finish: carbon
• Fitting information: Models with sport differential and without chassis reinforcement bars (visual check required) - with valves
• Material: aerospace-grade stainless steel
• Homologation: ECE / EC homologated
• Manufacturer: Milltek Sport (United Kingdom)

Compatible vehicles

• Audi S4 B9 3.0 Turbo V6 (with sport differential and without rear chassis reinforcement bars, Sedan/Estate, 2016-2018)
• Audi S5 F5 3.0 V6 T (with sport differential and without rear chassis reinforcement bars, Sportback, 2017-2018)

Not sure it fits your vehicle? Contact us with your VIN before ordering.

Most frequently asked questions

• What about the neighbors in the morning? The valves are controlled as on the original system: closed and quiet on startup or in comfort mode, fully open in sport mode.
• Homologation: this system is ECE / EC homologated, a real plus for driving with peace of mind and passing the roadworthiness test.
• Fitting: the system uses the original mounting points. A repair shop with the right equipment usually fits it in one to two hours.

Why choose Milltek Sport?

Milltek Sport designs and manufactures its exhausts in England, using mandrel-bent tubing to preserve the inner diameter and fitment developed on the vehicle. The result: a clean installation with no modifications needed, and a tone tuned to stay pleasant every day.

Further reading

• Exhaust valves: how they work and should you keep them?
• Exhaust systems and the French roadworthiness test (contrôle technique)