Finding the right cat-back for your Audi A4
A4 listings are split by engine, gearbox and body, so check all three. The B6 1.8T quattro has separate systems for the Cabriolet, the 163BHP five-speed Saloon and Avant (2001 to 2005) and the 190BHP six-speed Saloon and Avant (2003 to 2005). The B6 3.0 V6 quattro has one system for the Saloon, Avant and Cabriolet. On the B7 there is a 1.8T quattro Saloon and Avant system and one for the 2.0 TFSI quattro DTM.
For the B8, the 2.0 TFSI S line has separate manual and Tiptronic systems, each covering two-wheel-drive and quattro Saloons and Avants. Diesel owners can choose systems for the two-wheel-drive 2.0 TDI S line (140 to 177PS), the 2.0 TDI 177PS quattro and the 3.0 TDI quattro. Depending on the listing, A4 systems come with twin or quad outlets.
Audi A4 B9 and B9.5: cat-back and downpipes
The B9 2.0 TFSI quattro Saloon and Avant without an OPF/GPF (from 2016) has a cat-back, a sports cat downpipe, which keeps a catalyst, and a de-cat downpipe, which is for off-road and competition use only and will fail an MOT emissions test. Both downpipes usually need an ECU remap. A separate cat-back is listed for the North American (NAS) B9.5 2.0 TFSI quattro without an OPF, from 2021.
Many A4 systems can be ordered resonated, for less drone on a long motorway drive, or non-resonated, and a Road+ part-resonated option is listed too. Tips include GT-80, GT-90, GT-100 and JET styles; see Milltek exhaust tip styles. For more performance, see the Audi S4 and Audi RS4 pages.
Buying an A4 exhaust from Milltek Exhaust Shop
Enter your reg in the lookup above the products to see the A4 parts that match your car. Every UK order ships free, we also send parts abroad, and you can pay through PayPal or Klarna. Prefer it fitted? Our Stoke-on-Trent workshop can do that.