Scope of delivery: - Downpipe for Audi S3 8L 209 hp TT 225 hp ø 76 mm stainless steel* - Includes gasket set: 2x gaskets, 2x screws with nuts and washers.Product description: The stainless steel ø 76mm downpipe significantly reduces backpressure, relieving the turbocharger, which in turn delivers more power, torque, and lower exhaust gas temperatures. The post-catalytic sensor must be deactivated. The downpipe is made of stainless steel except for the flanges, which are made of steel to prevent warping and thus avoid leaks. The flange surfaces are machined and the V-band connection is male/female, therefore self-sealing and self-centering. The connection to the turbocharger has a three-hole flange with a V-band connection attached. This is then connected to the first section of the downpipe, allowing the upper part of the downpipe to rotate. Two lambda sensor ports M18x1.5mm and an interlock flex pipe are welded in. The downpipe sits between the turbocharger and the exhaust system. The connection to the exhaust is as original.A 200 cell cat is recommended. A power output of up to 450 hp can be achieved, but of course the other components such as the exhaust system, injectors, manifold, intercooler, turbocharger must also be installed and the software must be adjusted accordingly. Upgrade turbochargers such as K04-023 plug & play also fit the downpipe. The downpipe is replaced 1:1 by the original.compatible with: - Audi TT 1.8T 225 hp Quattro (8N) (modifications are necessary for the convertible) - Audi S3 1.8T 209-225 hp Quattro (8L) - Seat Leon Cupra R 1M (a 2 hole flange must be purchased and welded to the exhaust)Optional: - Sport cat / racing cat 200 cell ø 102mm - L 250mm stainless steel metal cat with E-mark R103 up to Euro 4 & lambda sensor port 340123Registration: For individual approval according to §21 StVZO, please contact your TÜV inspector.Please note that installation of this item constitutes a modification, which results in the invalidation of the vehicle's operating license according to StVZO. Use on public roads is not permitted.