The ARK downpipe and test pipe are designed to get the most out of high revving race motors. We use 2.5" Piping SUS-304 Steel, Increases dyno proven Horsepower And Torque From Mid-Range To Redline. Each downpipe includes a Bung cap hole for O2 sensors and/or CEL Fixers without having to drill into your downpipe. ARK Downpipes with Test Pipe is a direct replacement for your stock downpipe and your secondary catalytic converters.Our H-pipes will bolt directly to your OEM exhaust and GRiP cat-back exhaust system; it might not fit all other aftermarket exhaust systems. ARK Advantages and Features: - All Bolt-on System - SUS304 Stainless Steel Construction - Fully Polished Finish, 2.5 inch Dual Piping - CNC Machined Flanges - Includes O2 Bungs - Exposed Micro TIG Welding Items Included: Downpipe, Test Pipe, Bolts, Gaskets, Hardware, Installation Guide *For all orders shipped outside the U.S. tax/duty/custom fees are not included *FOR OFF-ROAD USE ONLY, MAY GET A CEL*