Milltek provide a range of large bore down pipe options for the Focus ST mk3 250. We recommend ALL downpipe installs be accompanied by a re-map of your ECU as well on install. We offer an ECE approved high quality hi flow HJS catted version, a Milltek catted version with high flow 200 CEL cat, and a motorsport only DECAT downpipe. A high flow down pipe allows more efficient expelling of exhaust gasses and better turbo efficiency, adding up to more power and responsiveness when combined with a good remap. FITMENT: All Petrol Focus mk3 ST 250 models including estate. Connectivity:HJS high flow to OE or Milltek catMilltek 200 CEL high flow cat to Milltek catback ONLY (so not estate) DECAT downpipe to OE or Milltek cat.