{"product_id":"mad-bmw-f-g-chassis-5-b58-catted-downpipe-m240-340-m340-440-m440-540-w-no-cel-guarantee-bracket","title":"MAD BMW F \u0026 G Chassis 5\" B58 Catted Downpipe M240 340 M340 440 M440 540 W\/ No CEL Guarantee \u0026 Bracket","description":"\u003cp\u003eSwap your restrictive factory B58 downpipe for the MAD B58 Catted Downpipe and unlock real power, a deeper tone and dependable performance — all without tripping a check engine light. It's the upgrade for B58 owners who want more from the car with none of the headaches.\u003c\/p\u003e\n\u003ch3\u003ePerformance\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e300-cell high-flow catalytic converter\u003c\/strong\u003e for noticeable gains and a more aggressive note, while keeping the CEL off.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSmooth, high-flow piping\u003c\/strong\u003e that frees up exhaust flow for more horsepower, stronger torque and sharper throttle response.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 30 HP\u003c\/strong\u003e on stock turbos — even more on an upgraded setup.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlex section\u003c\/strong\u003e built in for long-term durability, with smooth bends that keep drone away.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eBuild \u0026amp; fit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePremium 304 stainless steel, engineered to handle extreme heat and tough conditions.\u003c\/li\u003e\n\u003cli\u003eDirect bolt-on to the factory exhaust — no cutting or welding.\u003c\/li\u003e\n\u003cli\u003eFully compatible with most aftermarket exhaust setups, and with right- and left-hand-drive cars.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eNo-CEL guarantee \u0026amp; warranty\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eIf a check engine light appears due to the catalytic converter, MAD replaces the downpipe free — valid for 2 years from purchase.\u003c\/li\u003e\n\u003cli\u003eLifetime warranty on the downpipe against manufacturer defects such as cracks in the pipe or welds.\u003c\/li\u003e\n\u003cli\u003e90-day return window; ships in 1–2 business days.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e2015+ BMW M240i \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2016–2019 BMW 340i \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2020–2024 BMW M340i \u0026amp; xDrive (does not fit 2025+)\u003c\/li\u003e\n\u003cli\u003e2016+ BMW 440i \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2016+ BMW 540i \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2016+ BMW 740i \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2017–2024 BMW X3 M40 (G01\/G02)\u003c\/li\u003e\n\u003cli\u003e2017–2024 BMW X4 M40 (G01\/G02)\u003c\/li\u003e\n\u003cli\u003e2019+ BMW X5 40i (G05) \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2019+ BMW X7 40i (G07) \u0026amp; xDrive\u003c\/li\u003e\n\u003cli\u003e2019+ BMW Z4 M40i (G29)\u003c\/li\u003e\n\u003cli\u003e2019+ Toyota Supra 3.0L\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eEmissions disclaimer:\u003c\/strong\u003e This product is not legal for sale or use on pollution-controlled vehicles operated on public roads and is intended for off-road, race, or closed-course competition use only. You are responsible for compliance with all applicable emissions laws; use on public roads may violate the Federal Clean Air Act (42 U.S.C. § 7522) and similar state laws. Please check your local laws before purchase and installation.\u003c\/p\u003e\n\u003cp\u003eShips from our Vancouver shop — KORE SPEED is proudly Canadian-owned, with no surprise cross-border duties for Canadian buyers. Fitment questions? Email \u003ca href=\"mailto:support@korespeed.com\"\u003esupport@korespeed.com\u003c\/a\u003e.\u003c\/p\u003e","brand":"MAD","offers":[{"title":"Default Title","offer_id":51574530244664,"sku":"MAD-120","price":949.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1775\/7947\/files\/WhatsApp_Image_2025-07-29_at_10.19.04_14df2edd__82456.1753979896.386.513.jpg?v=1764906245","url":"https:\/\/korespeed.com\/products\/mad-bmw-f-g-chassis-5-b58-catted-downpipe-m240-340-m340-440-m440-540-w-no-cel-guarantee-bracket","provider":"KORE SPEED","version":"1.0","type":"link"}