{"product_id":"stone-exhaust-bmw-b48-g20-330i-cat-back-exhaust-system","title":"Stone Exhaust Valved Cat-Back Exhaust for BMW 330i 430i (B48) G20 G21 G22 G23 G26 - Switchable\/Valvetronic, Active Valve OEM Actuator Plug-and-Play, xDrive \u0026 OPF\/GPF Compatible - BMW 3 Series\/4 Series Performance Rear Section - AP537","description":"\u003cdiv class=\"product__description rte\"\u003e\n  \n  \u003ch2\u003eStone Exhaust AP537 Valved Sports System for BMW 330i and 430i G‑Series\u003c\/h2\u003e\n  \n  \u003cp\u003eUnlock a richer soundtrack and sharper throttle response from your BMW 3 Series or 4 Series with the Stone Exhaust AP537 valved sports system. Designed specifically for G‑series 330i and 430i models powered by the B48 engine, this premium catback upgrade delivers a deeper tone when open, refined civility when closed and seamless plug‑in compatibility with the factory valve hardware. It is a true bolt-on performance exhaust that enhances daily driving and comes alive on spirited runs and track days, all without unwanted cabin boom.\u003c\/p\u003e\n  \n  \u003cp\u003eWe fit these systems in-house and run them on customer cars. Feedback is consistently excellent for fit, finish and the addictive B48 note. If you are searching for a BMW 330i sports exhaust, 430i performance system or a G‑series valved upgrade that looks OEM and sounds special, this is the one.\u003c\/p\u003e\n  \n  \u003ch3\u003eKey reasons to choose Stone AP537\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eDirect connection to the factory flap actuator for true plug‑and‑play valve operation\u003c\/li\u003e\n    \u003cli\u003eOptional Stone valve control kit with OBD plug for manual open and close plus automatic RPM‑based logic\u003c\/li\u003e\n    \u003cli\u003eCarefully tuned for zero motorway drone and refined cruising\u003c\/li\u003e\n    \u003cli\u003eDeveloped on Stone’s in‑house dyno with measurable performance improvements\u003c\/li\u003e\n    \u003cli\u003eOne‑piece layout for optimal flow and straightforward installation\u003c\/li\u003e\n    \u003cli\u003e3D digitised and reverse‑engineered from the stock system for precise fitment\u003c\/li\u003e\n    \u003cli\u003e7‑axis CNC mandrel bending retains up to 98 percent roundness for smooth gas velocity\u003c\/li\u003e\n    \u003cli\u003eCrisscross and overlapping welds at high‑temperature zones for durability\u003c\/li\u003e\n    \u003cli\u003eRobotic spot welding for consistent penetration and long‑term strength\u003c\/li\u003e\n    \u003cli\u003eFree PPF\/OPF delete harness supplied for particulate filter cars to prevent warning lights without ECU coding\u003c\/li\u003e\n    \u003cli\u003eCompatible with rear‑wheel drive and all wheel drive variants\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eWhat you will notice\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eDeeper, cleaner B48 voice with valves open and a subtle, refined tone when closed\u003c\/li\u003e\n    \u003cli\u003eSmoother flow from precision‑formed pipework\u003c\/li\u003e\n    \u003cli\u003eReal‑world, dyno‑validated gains with a more engaging driving experience\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003eRecommended pairing\u003c\/h3\u003e\n  \u003cp\u003eFrequently combined with the Stone B48 catless downpipe or Stone B48 Eddy catalytic downpipe for additional performance and sound enhancement.\u003c\/p\u003e\n  \n  \u003ch3\u003eCompatibility\u003c\/h3\u003e\n  \u003cp\u003eFor BMW G‑series 3 Series and 4 Series with the B48 engine:\u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003e3 Series G20 Saloon 330i\u003c\/li\u003e\n    \u003cli\u003e3 Series G21 Touring 330i\u003c\/li\u003e\n    \u003cli\u003e4 Series G22 Coupe 430i\u003c\/li\u003e\n    \u003cli\u003e4 Series G23 Convertible 430i\u003c\/li\u003e\n    \u003cli\u003e4 Series G26 Gran Coupe 430i\u003c\/li\u003e\n    \u003cli\u003eFits both RWD and AWD models, including particulate filter vehicles\u003c\/li\u003e\n  \u003c\/ul\u003e\n  \n  \u003ch3\u003ePPF\/OPF information\u003c\/h3\u003e\n  \u003cp\u003eA complimentary harness is included to enable installation on petrol particulate filter cars without triggering error messages, so no ECU coding is required.\u003c\/p\u003e\n  \n  \u003ch3\u003eR\u0026amp;D and manufacturing\u003c\/h3\u003e\n  \u003cp\u003eStone digitally maps the OE system to capture diameter, bend radius and routing, then simulates gas flow and heat load before production. The result is precision pipework produced by 7‑axis CNC bending, reinforced by crisscross and overlapping welds at critical joints and robotic spot welding for repeatability.\u003c\/p\u003e\n  \n  \u003cdiv style=\"margin: 12px 0;\"\u003e\n    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0284\/6300\/5795\/files\/1_9336c8b0-c9ea-4822-891c-83490f630707.jpg?v=1572705528\" alt=\"Stone Exhaust 3D scanning and reverse engineering for BMW G‑series B48\"\u003e\n  \u003c\/div\u003e\n  \n  \u003cdiv style=\"margin: 12px 0;\"\u003e\n    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0284\/6300\/5795\/files\/bending.jpg?v=1572739395\" alt=\"Stone Exhaust 7‑axis CNC bending precision pipework\"\u003e\n  \u003c\/div\u003e\n  \n  \u003cdiv style=\"margin: 12px 0;\"\u003e\n    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0284\/6300\/5795\/files\/Stone_Exhaust_Art_of_Welding_-_1_1024x1024.jpg?v=1572828150\" alt=\"Stone Exhaust welding quality crisscross and overlapping technique\"\u003e\n  \u003c\/div\u003e\n  \n  \u003cdiv style=\"margin: 12px 0;\"\u003e\n    \u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0284\/6300\/5795\/files\/Stone_Exhaust_Art_of_Welding_-_2_1024x1024.jpg?v=1572828178\" alt=\"Stone Exhaust robotic spot welding for strength and precision\"\u003e\n  \u003c\/div\u003e\n  \n  \u003ch3\u003eSound check videos\u003c\/h3\u003e\n  \u003cdiv style=\"margin: 12px 0;\"\u003e\n    \u003ciframe width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/gCvoqm8agug\" title=\"Stone Exhaust B48 Valved Sports System Sound Test\" frameborder=\"0\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen\u003e\u003c\/iframe\u003e\n  \u003c\/div\u003e\n  \u003cdiv style=\"margin: 12px 0;\"\u003e\n    \u003ciframe width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/js0MWGt0SFg\" title=\"Stone Eddy Catalytic Downpipe with Valved Sports System\" frameborder=\"0\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen\u003e\u003c\/iframe\u003e\n  \u003c\/div\u003e\n  \n  \u003ch3\u003eInstallation and fitting\u003c\/h3\u003e\n  \u003cp\u003eDirect bolt‑on fit with factory valve integration. Professional installation recommended. MJ Modifications offers expert fitting in Warwickshire. Request a quote at \u003ca href=\"mailto:info@mjmodifications.co.uk\"\u003einfo@mjmodifications.co.uk\u003c\/a\u003e.\u003c\/p\u003e\n  \n  \u003ch3\u003eWarranty\u003c\/h3\u003e\n  \u003cp\u003eStone Exhaust 2‑year warranty.\u003c\/p\u003e\n  \n  \u003ch3\u003ePart number\u003c\/h3\u003e\n  \u003cp\u003e\u003cstrong\u003eAP537\u003c\/strong\u003e\u003c\/p\u003e\n  \n  \u003ch3\u003eSearch-friendly terms\u003c\/h3\u003e\n  \u003cp\u003eBMW 330i sports exhaust, BMW 430i performance exhaust system, G‑series 3 Series exhaust upgrade, G‑series 4 Series exhaust upgrade, B48 valve controlled exhaust, BMW petrol particulate filter compatible exhaust, PPF back exhaust, OPF back system, BMW performance catback, BMW valved exhaust upgrade, 330i saloon exhaust, 330i touring exhaust, 430i coupe exhaust, 430i convertible exhaust, 430i gran coupe exhaust, BMW G‑series B48 exhaust, Stone Exhaust AP537, plug and play exhaust for BMW, no drone BMW exhaust, track day friendly exhaust, daily driver friendly exhaust.\u003c\/p\u003e\n  \n\u003c\/div\u003e","brand":"Stone Exhaust","offers":[{"title":"OEM Integrated Valved \/ Flat Cut Gloss Carbon Fiber (102mm)","offer_id":55977881862530,"sku":null,"price":2427.84,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0871\/5445\/8937\/files\/1020CG_FlatCutGlossCarbonFibre_102mm-2_1024x1024_2x_2abc7f66-6ffe-4503-b306-ab2e6611bb19.webp?v=1763377154","url":"https:\/\/mjmodifications.co.uk\/products\/stone-exhaust-bmw-b48-g20-330i-cat-back-exhaust-system","provider":"MJ Modifications","version":"1.0","type":"link"}