Milltek for the S4 B5, B6, B7 and B8
The B5 2.7T quattro has a single cat-back. The 4.2 V8 B6 (2003 to 2005) and B7 (2004 to 2009) each have a cat-back and a set of cat replacement pipes, covering the Saloon, Avant and Cabriolet. The supercharged 3.0 V6 has separate cat-backs for the B8 (2009 to 2012) and the B8.5 (2012 to 2016).
Matching parts to your S4 B9
Every B9 3.0 Turbo V6 part is for Saloon and Avant models without a GPF (from 2016) and is listed four ways. First, the differential: cars without the sport differential take the Non Sport Diff version, and cars with a sport differential but no brace bars take the Sport Diff without Brace Bars version. Second, the drive side: UK cars are right-hand drive, so choose RHD; left-hand-drive cars take LHD.
Each of those four combinations has a cat-back, a sports cat downpipe, HJS Tuning ECE downpipes, a cat replacement pipe and Active Valve Control. If you are not sure whether your S4 has the sport differential, check its build specification before you order.
Sound, valves and tips for the S4
B9 cat-backs come valved or non-valved and resonated or non-resonated, with a Race option on some. Resonated systems are the quieter choice with less drone on the motorway. A valved system can be paired with Milltek's Active Valve Control, listed with our electronics. Tips include GT-90 and GT-100 round tips, JET-100 in carbon fibre and ovals, in finishes from polished to burnt titanium; see Milltek exhaust tip styles.
Owners of the B9 S4 3.0 Bi-TDI Saloon or Avant (from 2019) can add Active Sound Control, an electronic sound unit rather than an exhaust.
S4 downpipes and road legality
Sports cat downpipes and HJS Tuning ECE downpipes keep a catalyst, so they suit a road car, though they usually need an ECU remap. Cat replacement pipes remove the catalysts: they are for off-road and competition use only and will fail an MOT emissions test. Coupé, Cabriolet and Sportback owners should use the Audi S5 range.
Buying S4 parts from Milltek Exhaust Shop
Start with the registration lookup at the top of the page, then check the differential and drive side in each title. UK delivery is on us, we ship around the world, PayPal and Klarna are both accepted, and we fit exhausts at our Stoke-on-Trent workshop.