{"product_id":"catless-downpipes-for-w222-mercedes-s550-m278-4-7l-v8-biturbo-2011-2017","title":"Catless Downpipes for Mercedes W222 C217 S550 - M278 4.7L V8 BiTurbo (2011–2017)","description":"\u003cdiv style=\"max-width: 1000px; margin: 0 auto; padding: 22px; font-family: ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif; color: #111; line-height: 1.6;\"\u003e\n\u003c!-- Fitment Badge --\u003e\n\u003cdiv style=\"display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fafafa; margin-bottom: 16px;\"\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eCatless Downpipe Set\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444;\"\u003e\n\u003cstrong\u003eS550\u003c\/strong\u003e • M278 BiTurbo V8 • 2011–2017\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Title --\u003e\n\u003ch2 style=\"margin: 0 0 8px 0; font-size: 22px; letter-spacing: -0.3px;\"\u003e2011–2017 Mercedes-Benz S550 M278 Catless Downpipes\u003cbr\u003e\u003cspan style=\"font-size: 15px; color: #555; font-weight: 500;\"\u003eHigh-flow stainless downpipe set for M278 applications\u003c\/span\u003e\n\u003c\/h2\u003e\n\n\u003cp style=\"margin: 0 0 14px 0; color: #333;\"\u003eReduce exhaust restriction and improve turbo response with a \u003cstrong\u003ecatless downpipe set\u003c\/strong\u003e built for the \u003cstrong\u003e2011–2017 Mercedes-Benz S550 (M278 Bi-turbo V8, W222 sedan \u0026amp; C217 coupe chassis)\u003c\/strong\u003e. Designed to increase exhaust flow for faster spool and stronger mid-range response—especially when paired with proper ECU calibration. Owners commonly report noticeably quicker turbo spool-up and improved throttle response after installation.\u003c\/p\u003e\n\n\u003c!-- Trust \/ What You Get --\u003e\n\u003cdiv style=\"padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fff; box-shadow: 0 1px 0 rgba(0,0,0,0.02); margin-bottom: 18px;\"\u003e\n\u003cdiv style=\"font-weight: 800; margin-bottom: 6px;\"\u003eWhat’s Included\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444;\"\u003eComplete left\/right downpipe set (as pictured). Hardware\/gaskets are not included unless shown in photos.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Quick Specs --\u003e\n\u003cdiv style=\"display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px; margin-bottom: 18px;\"\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; padding: 12px 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-size: 12px; color: #666; margin-bottom: 4px;\"\u003eEngine\u003c\/div\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eM278 Bi-Turbo V8\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; padding: 12px 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-size: 12px; color: #666; margin-bottom: 4px;\"\u003eChassis\u003c\/div\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eS-Class (W222 sedan \u0026amp; C217 coupe)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; padding: 12px 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-size: 12px; color: #666; margin-bottom: 4px;\"\u003eType\u003c\/div\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eCatless \/ High-Flow\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Benefits --\u003e\n\u003ch3 style=\"margin: 18px 0 8px 0; font-size: 16px;\"\u003eWhy Upgrade the Factory Downpipes?\u003c\/h3\u003e\n\u003cul style=\"margin: 0 0 14px 18px; padding: 0; color: #333;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved exhaust flow:\u003c\/strong\u003e helps reduce backpressure for more efficient turbo operation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSharper response:\u003c\/strong\u003e faster spool and stronger mid-range pull.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMore aggressive sound:\u003c\/strong\u003e increases exhaust volume and tone (varies by setup).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ECU Tune CTA --\u003e\n\u003cdiv style=\"background: #fff; border: 1px solid #eaeaea; border-radius: 14px; padding: 16px; margin: 16px 0; text-align: center;\"\u003e\n\u003cdiv style=\"font-weight: 900; font-size: 16px; margin: 0 0 6px; color: #111;\"\u003eRecommended Next Step: ECU Tuning\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; color: #555; margin: 0 0 12px;\"\u003eA catless setup may trigger a check engine light without proper ECU calibration or sensor management.\u003c\/div\u003e\n\u003ca href=\"https:\/\/benzunitedparts.com\/products\/custom-ecu-tuning-for-e63-cls63\" style=\"display: inline-block; background: #111; color: #fff; padding: 12px 24px; border-radius: 8px; text-decoration: none; font-weight: 700; font-size: 15px; border: none; box-shadow: 0 2px 4px rgba(0,0,0,0.1); transition: all 0.2s ease;\"\u003eView ECU Tune Options\u003c\/a\u003e\n\u003cdiv style=\"font-size: 12px; color: #777; margin-top: 10px;\"\u003eIf you have a different platform\/tune listing for M278, link this button to that product instead.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Fitment --\u003e\n\u003ch3 style=\"margin: 16px 0 10px 0; font-size: 16px;\"\u003eFitment\u003c\/h3\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; background: #fff; padding: 12px 14px;\"\u003e\n\u003cul style=\"margin: 0; padding-left: 18px; line-height: 1.7; color: #333;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eMercedes-Benz S550\u003c\/strong\u003e – \u003cstrong\u003e2011–2017\u003c\/strong\u003e (W222 sedan \u0026amp; C217 coupe chassis)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine:\u003c\/strong\u003e M278 twin-turbo V8\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; color: #555; margin-top: 10px; margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eFitment tip:\u003c\/strong\u003e Please confirm your chassis code (W222 or C217) and engine (M278) before ordering. If you’re unsure, message us your VIN (optional) and we’ll help verify compatibility.\u003c\/div\u003e\n\n\u003c!-- Important Notice --\u003e\n\u003cdiv style=\"background: #ffeded; border: 1px solid #f5c2c7; border-radius: 14px; padding: 16px; margin: 18px 0;\"\u003e\n\u003ch3 style=\"margin: 0 0 6px; color: #cc0000; font-size: 18px;\"\u003eImportant Use Notice\u003c\/h3\u003e\n\u003cp style=\"margin: 0; color: #7a1c1c;\"\u003eThis product is intended for off-road or competition use only. Installation may not comply with local emissions regulations and may result in a check engine light without proper tuning.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003c!-- Install \/ Notes --\u003e\n\u003cdiv style=\"background: #fff; border: 1px solid #eaeaea; border-radius: 14px; padding: 16px; margin: 16px 0;\"\u003e\n\u003ch3 style=\"margin: 0 0 8px; font-size: 16px; font-weight: 900;\"\u003eInstallation Notes\u003c\/h3\u003e\n\u003cul style=\"margin: 0; padding-left: 18px; line-height: 1.7; color: #333;\"\u003e\n\u003cli\u003eProfessional installation recommended.\u003c\/li\u003e\n\u003cli\u003eInspect\/replace gaskets and hardware as needed during installation.\u003c\/li\u003e\n\u003cli\u003eRe-check for leaks after initial heat cycles.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003c!-- Shipping \/ Returns --\u003e\n\u003cdiv style=\"margin-top: 18px; padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fafafa;\"\u003e\n\u003cdiv style=\"font-weight: 800; margin-bottom: 6px;\"\u003eShipping \u0026amp; Returns\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444;\"\u003eFast shipping. \u003cstrong\u003e30-day returns\u003c\/strong\u003e accepted for unused and uninstalled items in original packaging. Installed\/modified exhaust components are not eligible for return.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Support --\u003e\n\u003cdiv style=\"margin-top: 18px; padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-weight: 800; margin-bottom: 6px;\"\u003eNeed help confirming fitment?\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444; margin-bottom: 10px;\"\u003eMessage us your VIN (optional) or confirm your year\/model and engine (M278) and we’ll help verify before you order.\u003c\/div\u003e\n\u003ca href=\"mailto:benzunitedparts@gmail.com?subject=2011-2017%20S550%20M278%20Downpipes%20Fitment%20Help\" style=\"display: inline-block; background: #111; color: #fff; padding: 12px 24px; border-radius: 8px; text-decoration: none; font-weight: 700; font-size: 15px; border: none; box-shadow: 0 2px 4px rgba(0,0,0,0.1); transition: all 0.2s ease;\"\u003eContact Us\u003c\/a\u003e\n\u003c\/div\u003e\n\n\u003c!-- FAQ Section - SEO \u0026 ChatGPT Optimized --\u003e\n\u003cdiv style=\"margin-top: 32px; padding: 20px; border: 1px solid #eaeaea; border-radius: 14px; background: #fff;\"\u003e\n\u003ch3 style=\"margin: 0 0 16px 0; font-size: 18px; font-weight: 800;\"\u003eFrequently Asked Questions\u003c\/h3\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eWill these catless downpipes fit my 2011-2017 Mercedes S550 on W222 or C217 chassis?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eYes — these M278 catless downpipes are a direct fit for all 2011–2017 S550 models (W222 sedan \u0026amp; C217 coupe chassis) with the M278 bi-turbo 4.7L V8.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eDo I need a tune with S550 M278 catless downpipes?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eHighly recommended. A catless setup will usually trigger a check engine light without proper ECU tuning or O2 sensor spacers.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eWhat performance gains can I expect from 2011-2017 S550 downpipes?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eNoticeable improvement in turbo spool, throttle response, and mid-range torque when paired with tuning. Many owners report stronger acceleration and a more responsive feel.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eAre these high-flow downpipes loud?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eThey produce a deeper, more aggressive exhaust note than stock catalytic converters. Sound level depends on your full exhaust setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eWill these work on W222 S550 sedan and C217 S550 Coupe?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eYes. The downpipe set is designed for both the W222 sedan and C217 coupe chassis with the M278 engine.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"BenzUnited Parts","offers":[{"title":"Default Title","offer_id":46717188669615,"sku":null,"price":849.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0631\/8718\/9935\/files\/w222-s63-amg-m157-catless-downpipes-stainless.jpg?v=1772305144","url":"https:\/\/benzunitedparts.com\/products\/catless-downpipes-for-w222-mercedes-s550-m278-4-7l-v8-biturbo-2011-2017","provider":"BenzUnited Parts","version":"1.0","type":"link"}