{"title":"2020-2026 GM 2500HD\/3500HD 6.6L L5P Duramax Downpipes","description":"\u003cdiv\u003e\n\u003cinput type=\"checkbox\" class=\"read-more-state\" id=\"post-1\"\u003e\n\u003cp class=\"read-more-wrap\"\u003eUpgrading the restrictive factory downpipe found on your 2020-2026 GM 6.6L Duramax L5P is one of the easiest ways to enhance the sound and performance of your rig. At Alligator Performance, we offer a variety of aftermarket downpipe kits that offer a simple solution to boost your truck’s power, torque, and fuel economy while delivering an aggressive new exhaust tone that will be sure to command attention around every corner. \u003cspan class=\"read-more-target\"\u003e \u003cspan class=\"headerspam\"\u003e\u003cstrong\u003eGM Duramax Fitments:\u003c\/strong\u003e 2020, 2021, 2022, 2023, 2024, 2025, 2026 GM 6.6L Duramax.\u003c\/span\u003e \u003cspan class=\"headerspam\"\u003e\u003cstrong\u003eSubmodel Fitments:\u003c\/strong\u003e WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali.\u003c\/span\u003e \u003cspan class=\"headerspam\"\u003eSome exceptions apply, please see individual product pages for specific fitments.\u003c\/span\u003e \u003c\/span\u003e\u003c\/p\u003e\n\u003clabel for=\"post-1\" class=\"read-more-trigger\"\u003e\u003c\/label\u003e\n\u003c\/div\u003e","products":[{"product_id":"wehrli-100129-3-5-down-pipe-17-19-duramax-l5p","title":"Wehrli 100129 3.5\" inch Down Pipe | 2017-2026 GM Silverado\/Sierra 2500HD\/3500HD 6.6L Duramax","description":"\u003cp\u003e\u003cstrong\u003eFeatures:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e3.5-inch diameter for better exhaust flow\u003c\/li\u003e\n\u003cli\u003eReplaces crushed factory downpipe section\u003c\/li\u003e\n\u003cli\u003eHigh-temp black ceramic coated finish\u003c\/li\u003e\n\u003cli\u003eHeat wrap installed for thermal protection\u003c\/li\u003e\n\u003cli\u003eEmissions compliant, no tuning required\u003c\/li\u003e\n\u003cli\u003eConnects to factory 4-bolt flange system\u003c\/li\u003e\n\u003cli\u003eIncludes sensor bungs for OEM compatibility\u003c\/li\u003e\n\u003cli\u003eImproves throttle response and turbo efficiency\u003c\/li\u003e\n\u003cli\u003eFabricated steel construction for durability\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eImproved Exhaust Flow for GM 6.6L Duramax\u003c\/h4\u003e\n\u003cp\u003eIf you’re looking to free up exhaust flow on your L5P Duramax without getting into tuning or emissions issues, the Wehrli 3.5\" Down Pipe is one of the smartest upgrades you can make. Designed for 2017–2026 Silverado and Sierra 2500HD\/3500HD trucks with the 6.6L Duramax, this pipe replaces the restrictive, crushed factory unit with a high-flow, emissions-compliant solution that bolts right in. From a performance standpoint, the factory downpipe is a known bottleneck. It’s pinched and bent in a way that restricts flow, especially as exhaust gas volume increases under load or during towing. Wehrli solves that with a smooth, full 3.5-inch pipe that maintains consistent diameter throughout. That means better turbo efficiency, quicker spool, and improved throttle response, especially when paired with other upgrades like piping kits or tuning down the road.\u003c\/p\u003e\n\u003ch4\u003eHigh-Quality Construction with Direct-Fit Install\u003c\/h4\u003e\n\u003cp\u003eThe construction is exactly what you’d expect from Wehrli. It’s fabricated from quality steel, then finished in a high-temp black ceramic coating to handle the intense heat coming off the turbo. On top of that, they’ve already pre-installed a heat wrap around the pipe, which helps cut down underhood temperatures and protects surrounding components. It’s a clean, professional-grade finish right out of the box. Installation is straightforward. This pipe connects directly to the DOC (Diesel Oxidation Catalyst) outlet flange and mates up with the factory front pipe using the OEM-style 4-bolt flange. No tuning is needed, and it retains compatibility with your emissions system. All sensor bungs are in place, so everything functions just like stock, with the added benefit of better flow and sound.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026 GM Silverado\/Sierra 2500HD\/3500HD 6.6L Duramax\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNotes:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFits 2017–2026 Silverado and Sierra HD 6.6L Duramax\u003c\/li\u003e\n\u003cli\u003eNot legal for sale or use in California\u003c\/li\u003e\n\u003cli\u003eReplaces restrictive factory downpipe for smoother flow\u003c\/li\u003e\n\u003cli\u003eNo tuning required, works with stock ECU\u003c\/li\u003e\n\u003cli\u003eDirect bolt-on using OEM 4-bolt flange\u003c\/li\u003e\n\u003cli\u003eSensor bungs included for full factory compatibility\u003c\/li\u003e\n\u003cli\u003ePre-installed heat wrap reduces underhood temperatures\u003c\/li\u003e\n\u003cli\u003eBlack ceramic coating protects against extreme heat\u003c\/li\u003e\n\u003cli\u003eDurable steel construction built for long service life\u003c\/li\u003e\n\u003cli\u003eReplaces GM factory downpipe part number 12671086\u003c\/li\u003e\n\u003cli\u003eWorks best when paired with other airflow upgrades\u003c\/li\u003e\n\u003cli\u003eShips quickly with straightforward installation process\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Wehrli Custom Fab","offers":[{"title":"Default Title","offer_id":49527040114972,"sku":"WCF100129","price":334.65,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0738\/2279\/8108\/files\/100129_2.jpg?v=1722363041"},{"product_id":"ppe-117000800-35-inch-304-stainless-steel-down-pipe-17-24-gm-66l-duramax","title":"PPE 117000800 3.5-inch 304 Stainless Steel Down Pipe | 2017-2025 GM Silverado\/Sierra 2500HD\/3500HD 6.6L Duramax","description":"\u003cp\u003e\u003cstrong\u003eFeatures:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFull 304 stainless steel.\u003c\/li\u003e\n\u003cli\u003eSmooth, round construction.\u003c\/li\u003e\n\u003cli\u003eReplaces crushed oval-shaped stock down pipe.\u003c\/li\u003e\n\u003cli\u003eIncludes a woven titanium sleeve.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eDesigned for Longevity \u0026amp; Improved Exhaust Flow\u003c\/h4\u003e\n\u003cp\u003eUpgrade your vehicle's performance with the PPE Stainless Steel Down Pipe. Say goodbye to your crushed oval-shaped stock down pipe and replace it with our smooth, round, and durable full 304 stainless steel down pipe. Designed for longevity and improved exhaust flow, this down pipe enhances your vehicle's efficiency and power. Additionally, it includes a woven titanium sleeve that effectively reduces engine bay temperatures, ensuring optimal performance under any condition. Choose PPE for a reliable, high-quality upgrade that makes a difference.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025 GM Silverado\/Sierra 2500HD\/3500HD 6.6L Duramax\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNotes:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFits 2017–2025 Silverado and Sierra 6.6L Duramax\u003c\/li\u003e\n\u003cli\u003eMade from full 304 stainless steel\u003c\/li\u003e\n\u003cli\u003eSmooth round design replaces restrictive stock pipe\u003c\/li\u003e\n\u003cli\u003eIncludes woven titanium sleeve for heat protection\u003c\/li\u003e\n\u003cli\u003eLowers exhaust temps and improves turbo response\u003c\/li\u003e\n\u003cli\u003eWelded flanges provide a strong leak-free connection\u003c\/li\u003e\n\u003cli\u003eKeeps factory sensor port for OEM compatibility\u003c\/li\u003e\n\u003cli\u003eDirect bolt-on install with no cutting required\u003c\/li\u003e\n\u003cli\u003eWorks with stock or aftermarket up-pipes\u003c\/li\u003e\n\u003cli\u003eBuilt for long-term durability and performance\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"PPE","offers":[{"title":"Default Title","offer_id":49527590715676,"sku":"PPE117000800","price":197.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0738\/2279\/8108\/files\/ppe117000800_1.jpg?v=1722359493"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0738\/2279\/8108\/collections\/GM_Duramax_Downpipes_Thumb_1.jpg?v=1728500412","url":"https:\/\/www.alligatorperformance.com\/collections\/2020-2026-gm-duramax-66l-l5p-downpipes.oembed","provider":"Alligator Performance","version":"1.0","type":"link"}