{"product_id":"stone-exhaust-bmw-b58-f30-f32-cat-back-exhaust-system-340i-440i","title":"Stone Exhaust BMW 340i 440i B58 Valved Cat-Back (Catback) Performance Exhaust F3x F30 F31 F32 F33 F36 - Switchable\/Valvetronic, OEM Valve Integration + OBD Controller, OPF\/GPF Delete Friendly, Twin\/Dual or Quad Tip Back Box Upgrade (AP514B58\/AP514QB58)","description":"\u003cdiv class=\"product__description rte\"\u003e\n  \n  \u003cp\u003e\u003cstrong\u003eTransform the soundtrack and response of your F3x 3 Series and 4 Series B58\u003c\/strong\u003e with this switchable performance exhaust for 340i and 440i. Engineered for drivers who want an easy bolt-on upgrade with factory-style valve operation, rich tone and precision build quality, it’s the refined yet aggressive system our customers consistently rate as a top-tier choice. We’ve fitted this setup on multiple cars and the feedback has been superb: whisper-quiet when you want it, spine-tingling when you don’t, and perfect alignment on every install.\u003c\/p\u003e\n  \n  \u003ch2\u003eWhat makes this system stand out\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eFactory valve strategy retained for seamless quiet-to-loud transitions\u003c\/li\u003e\n    \u003cli\u003ePlug-in OBDII controller included for reliable, hassle-free valve control\u003c\/li\u003e\n    \u003cli\u003eOne-piece architecture for smooth gas flow and spot-on fitment\u003c\/li\u003e\n    \u003cli\u003ePrecision-formed pipework with advanced machine welding for strength and consistency\u003c\/li\u003e\n    \u003cli\u003eDeveloped using 3D scanning, reverse engineering and simulation for the B58 platform\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eOPF and GPF friendly solution included\u003c\/h3\u003e\n  \u003cp\u003eRunning a particulate filter on your F3x B58? A dedicated OPF delete solution is supplied at no extra cost, allowing installation on OPF-equipped vehicles without warning lights or ECU coding. Ideal for owners searching for a GPF workaround on 340i and 440i models.\u003c\/p\u003e\n  \n  \u003ch3\u003eAcoustic character you can live with\u003c\/h3\u003e\n  \u003cp\u003eValve closed gives you a calm, refined drive with minimal cabin intrusion. Open the valve and you unlock a sharper, motorsport-inspired note that lets the B58 sing. Daily comfort meets weekend thrills in one system.\u003c\/p\u003e\n  \n  \u003ch3\u003eBuilt with serious engineering\u003c\/h3\u003e\n  \u003cp\u003eEach unit is digitally measured against original hardware for millimetre-accurate routing. 7-axis CNC bending targets exceptional roundness and minimises deformation on tight radii, helping reduce turbulence. Overlapping and crisscross weld techniques deliver durability where temperatures peak, and the finish looks as good as it performs.\u003c\/p\u003e\n  \n  \u003ch3\u003eValve control options\u003c\/h3\u003e\n  \u003cp\u003eThe exhaust integrates with the car’s original strategy out of the box. Want manual control at your fingertips? Add the optional Stone Valvetronic System single-valve controller to switch volume levels remotely.\u003c\/p\u003e\n  \n  \u003ch2\u003eFitment\u003c\/h2\u003e\n  \u003cp\u003e\u003cstrong\u003eBMW 3 Series\u003c\/strong\u003e\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eF30 LCI \/ F31 LCI 340i \/ 340i xDrive 2014 to 2018\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \u003cp\u003e\u003cstrong\u003eBMW 4 Series\u003c\/strong\u003e\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003eF32 \/ F32 LCI 440i \/ 440i xDrive 2015 to 2017\u003c\/li\u003e\n    \u003cli\u003eF33 440i 2015 to 2017 \/ 440i xDrive 2013 to 2017\u003c\/li\u003e\n    \u003cli\u003eF33 LCI 440i \/ 440i xDrive 2016 to 2018\u003c\/li\u003e\n    \u003cli\u003eF36 440i \/ 440i xDrive 2015 to 2017\u003c\/li\u003e\n    \u003cli\u003eF36 LCI 440i \/ 440i xDrive 2016 to 2018\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eTailpipe styles and part numbers\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAP514B58\u003c\/strong\u003e - Twin outlet with dual tips - suits the original rear bumper\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAP514QB58\u003c\/strong\u003e - Twin outlet with quad tips - requires M Sport rear bumper\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003ePerfect pairing for more flow\u003c\/h3\u003e\n  \u003cp\u003eFrequently combined with B58 downpipes for a bigger performance and sound gains:\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eStone Exhaust BMW B58 Catless Performance Downpipe\u003c\/strong\u003e (covers M140i, M240i, 440i, 540i, 740i, X5 M40i)\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eStone Exhaust BMW B58 Eddy Catalytic Performance Downpipe\u003c\/strong\u003e (covers M140i, M240i, 440i, 540i, 740i, X5 M40i)\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \u003cp\u003eMatch a B58 downpipe with this rear section for a sharper throttle response and deeper tone.\u003c\/p\u003e\n  \n  \u003ch2\u003eWhy enthusiasts choose this upgrade\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eOEM-level valve integration for effortless everyday use\u003c\/li\u003e\n    \u003cli\u003ePlug-and-play installation with supplied OBDII valve controller\u003c\/li\u003e\n    \u003cli\u003eOne-piece layout for optimised exhaust gas velocity\u003c\/li\u003e\n    \u003cli\u003eMachine welding for repeatable quality and long-term reliability\u003c\/li\u003e\n    \u003cli\u003eData-driven R\u0026amp;D with 3D scanning and reverse engineering\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eWarranty\u003c\/h3\u003e\n  \u003cp\u003eBacked by a 2 year manufacturer warranty.\u003c\/p\u003e\n  \n  \u003ch3\u003eProfessional fitting\u003c\/h3\u003e\n  \u003cp\u003eWant it installed by specialists who know these cars inside out? MJ Modifications offers fitting at our Warwickshire workshop. Email \u003ca href=\"mailto:info@mjmodifications.co.uk\"\u003einfo@mjmodifications.co.uk\u003c\/a\u003e for a quote and booking.\u003c\/p\u003e\n  \n  \u003ch2\u003eSearch-friendly terms customers use\u003c\/h2\u003e\n  \u003cp\u003eIf you’re browsing for a 3 Series 340i sports exhaust, 4 Series 440i performance back box, B58 switchable system, quad outlet conversion, twin exit tips, F30 F31 F32 F33 F36 exhaust upgrade, GPF friendly exhaust solution, plug-in valve controller, F3x 340i muffler, 440i rear section, or B58 sound upgrade, this is the premium choice that delivers sound, quality and fitment.\u003c\/p\u003e\n  \n\u003c\/div\u003e","brand":"Stone Exhaust","offers":[{"title":"Dual Exit with Twin Tailpipes \/ Require Original Bumper \/ Flat Cut Gloss Carbon Fiber (82mm)","offer_id":56008717009282,"sku":null,"price":3256.03,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0871\/5445\/8937\/files\/8200CG_FlatCutGlossCarbonFiber82mmExhuastTailpipes_1024x1024_2_1946x_d103f032-b268-457d-a860-73967dd6a690.png?v=1764091266","url":"https:\/\/mjmodifications.co.uk\/products\/stone-exhaust-bmw-b58-f30-f32-cat-back-exhaust-system-340i-440i","provider":"MJ Modifications","version":"1.0","type":"link"}