{"product_id":"fass-drop-in-series-fuel-system-difsl5p1001-2017-2024-6-6l-duramax-l5p-see-fitment-notes","title":"FASS DROP-IN SERIES FUEL SYSTEM DIFSL5P1001 | 2017-2024 6.6L DURAMAX L5P (see fitment notes)","description":"\u003cp\u003eUpgrade the fuel filtration on your GM 6.6L Duramax L5P with the FASS DIFSL5P1001 Drop-In Series Fuel System. Engineered as a straightforward bolt-in filtration upgrade, this system retains the factory in-tank lift pump while providing advanced fuel filtration, water separation, and air removal to help protect the L5P's high-pressure fuel injection system.\u003c\/p\u003e\n\n\u003cp\u003eThe FASS Drop-In Series provides \u003cstrong\u003e2-micron absolute filtration\u003c\/strong\u003e and is designed to remove more than 99% of free and emulsified water from diesel fuel. The system also removes entrained air and vapor, helping provide cleaner, more consistent fuel to the injection system while increasing fuel lubricity by up to 10%.\u003c\/p\u003e\n\n\u003cp\u003eAt the center of the system is FASS' \u003cstrong\u003eExtreme Water Separator (XWS)\u003c\/strong\u003e technology. Its water-removal capability has been third-party tested to exceed 99%. When the XWS filter reaches its water-holding capacity, its design restricts fuel flow to help prevent contaminated fuel from continuing into critical injection system components.\u003c\/p\u003e\n\n\u003cp\u003eThe system also incorporates FASS \u003cstrong\u003ePerformance Radius Cuts (PRC)\u003c\/strong\u003e within the aluminum housing. These smooth internal transitions are designed to improve fuel flow and reduce restrictions, turbulence, and the potential reintroduction of air and vapor compared with sharp 90-degree internal passages.\u003c\/p\u003e\n\n\u003cp\u003eInstallation is designed to be straightforward with \u003cstrong\u003eno cutting, wiring, or additional vehicle modifications required\u003c\/strong\u003e. The system retains the factory Water-In-Fuel sensor functionality and works with either the factory plastic fuel filter cap or a compatible billet filter cap.\u003c\/p\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2-micron absolute filtration\u003c\/strong\u003e – Helps remove fine contaminants before they reach the high-pressure injection system\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOver 99% water separation\u003c\/strong\u003e – Extreme Water Separator technology removes free and emulsified water from diesel fuel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAir and vapor removal\u003c\/strong\u003e – Helps provide a more consistent supply of fuel to the injection system\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eImproved fuel lubricity\u003c\/strong\u003e – Removing entrained air and vapor can increase fuel lubricity by up to 10%\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRetains factory in-tank lift pump\u003c\/strong\u003e – Works with the existing factory fuel delivery system\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWater-In-Fuel sensor compatibility\u003c\/strong\u003e – Retains full functionality of the factory WIF sensor\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrop-in installation\u003c\/strong\u003e – No cutting, wiring, or additional vehicle modifications required\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePerformance Radius Cuts\u003c\/strong\u003e – Smooth internal passages help improve fuel flow and reduce turbulence and restriction\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFactory or billet filter cap compatible\u003c\/strong\u003e – Works with the factory plastic cap or a compatible billet filter cap\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHelps protect fuel system components\u003c\/strong\u003e – Cleaner fuel can help extend the service life of high-pressure injection system components\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSupports stock and modified trucks\u003c\/strong\u003e – Designed to operate without requiring calibration changes for installation\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLimited lifetime warranty\u003c\/strong\u003e – Backed by FASS according to current warranty terms\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFiltration Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFiltration Rating:\u003c\/strong\u003e 2 Micron Absolute\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWater Separation:\u003c\/strong\u003e Over 99% Free \u0026amp; Emulsified Water\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFuel Lubricity Improvement:\u003c\/strong\u003e Up to 10%\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFactory Lift Pump:\u003c\/strong\u003e Retained\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFactory Water-In-Fuel Sensor:\u003c\/strong\u003e Retained\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInstallation Type:\u003c\/strong\u003e Drop-In \/ Bolt-On\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eApplication Notes\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eDesigned for GM 6.6L Duramax L5P applications.\u003c\/li\u003e\n  \u003cli\u003eCompatible with Crew Cab Short Bed and Crew Cab Long Bed configurations as specified by FASS.\u003c\/li\u003e\n  \u003cli\u003eDesigned to install without cutting, wiring, or additional vehicle modifications.\u003c\/li\u003e\n  \u003cli\u003eWorks with the factory plastic fuel filter cap or a compatible billet filter cap.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eFitment:\u003c\/strong\u003e GM 6.6L Duramax L5P – Crew Cab Short Bed \u0026amp; Crew Cab Long Bed\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e DIFSL5P1001\u003c\/p\u003e","brand":"FASS Diesel Fuel Systems","offers":[{"title":"Default Title","offer_id":54066220171547,"sku":"DIFSL5P1001","price":479.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0962\/5757\/3147\/files\/Screenshot2026-09-29at2.02.20PM.png?v=1790743904","url":"https:\/\/wwmperformance.com\/products\/fass-drop-in-series-fuel-system-difsl5p1001-2017-2024-6-6l-duramax-l5p-see-fitment-notes","provider":"WWM Performance","version":"1.0","type":"link"}