Audi TT 180 / 225 quattro Coupe & Roadster From 1998 To 2006 Cat Replacement Pipes - Milltek Sport

The part is used to bypass the catalyst from the exhaust to create a ‘Decat’ system. Eliminating the catalyst will greatly enhance the gas-flow and the performance, adding significant Hp to your vehicle by removing the density of the catalyst in which exhaust gases are pushed through.