Description Milltek Sport Large-Bore Downpipes are perfect when looking to improve both performance and sound. These downpipes are fabricated with a larger diameter than standard OEM parts, meaning that there is significantly more space for more gas to exit the engine and pass-through, increasing efficiency. Combined with our Hi-Flow Sports Cat, you can expect a significant increase in performance and a noticeable difference in sound aesthetic. – For Fitment with both Milltek Sport and OE Cat-Back Systems – Stage 2 ECU Remap Required.