The new Milltek S4 Downpipes/Cats set is here! Awesome high-flow technology for your S4 (2000-2002)). Constructed of 60mm stainless with proper fitting of all sensors and mount points. Notice the full flex-pipe construction that insures proper fit, no matter what the temperature the entire system reaches.
Cats are premium quality with continuous stainless steel cores with high precious metal coating for long term emissions control. Tests of this setup by Milltek in the UK were producing an additional 20 ft-lbs of torque on a car with a "Stage 1" chip.