Scope of delivery: - Y-pipe downpipe for Audi A4 A6 1.8T B5 3B 3BG Quattro ø 63.5mm 2.5" made of stainless steelDescription: - The Y-pipe sits between the catalytic converter and the exhaust system. It is screwed onto the original catalytic converter or our plug&play 200 cell catalytic converter with item no. 340106 can be used. It has a cross-section of 63mm (original 54mm), an Interlook flex pipe and holder are installed. The larger downpipe reduces the back pressure, relieves the turbo and allows more power to be delivered, up to 330 hp depending on the components installed. The pipe is bent and only welded at the flex piece and flange. To get to the original exhaust system you have to use a reduction sleeve from 63>54mm, but usually larger exhaustsystems are used for tuning.suitable for: - Audi A4 1.8T B5 (8E) Quattro 150-180PS - Audi A6 1.8T C5 (4B2,4B5) Quattro 150-180PS - and also for the following upgrade turbochargers: - Borgwarner K04-015 53049880015 - Borgwarner K04-015 / K06 - Borgwarner K04-015 / TFSI compressor wheelRegistration: For an individual approval according to §21 StVZO please ask your TÜV inspector.We would like to point out that the installation of this article constitutes a modification which invalidates the vehicle's operating license in accordance with the StVZO. Not permitted for use on public roads.