FASS Drop-In Series Diesel Fuel System - 3.0L Duramax LM2/LZ0
Can I pick up my order or have it installed at your shop?
Can I pick up my order or have it installed at your shop?
Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at 636-429-7020 or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.
How do I know if this part fits my vehicle?
How do I know if this part fits my vehicle?
Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.
What if I need to return a product or it’s defective?
What if I need to return a product or it’s defective?
Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)
What's the lead time on custom or fabricated parts?
What's the lead time on custom or fabricated parts?
Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at 636-429-7020 and we’ll confirm current availability or estimated ship dates.
Description
Description
This is not a lift pump. The Drop-In Series is an air separation and filtration system that retains and works with your factory in-tank lift pump.
It replaces the plastic OEM single-filter housing with a CNC-machined 6061-T6 billet aluminum dual-filter housing, designed and built in-house. The system runs the OEM water separator element in series with the FASS XWS3002 Extreme Water Separator.
Keeping the OEM element is the point: it lets the factory water-in-fuel sensor stay on the dirty side, so the WIF light warns you before water reaches clean fuel. Systems that use a spin-on separator put the sensor on the clean side — by the time the light comes on, it's already too late.
Vehicle Fitment
| Years | Make & Model | Engine | Part Number |
|---|---|---|---|
| 2019-2026 | Chevrolet Silverado 1500 / GMC Sierra 1500 | 3.0L Duramax LM2 (2019-2022) / LZ0 (2023-2026) | DIFSLZ01001 |
| 2021-2026 | Chevrolet Tahoe / Suburban, GMC Yukon / Yukon XL | 3.0L Duramax LM2 (2021-2024) / LZ0 (2025-2026) | DIFSLZ02001 |
| 2021-2024 | Cadillac Escalade / Escalade ESV | 3.0L Duramax LM2 | DIFSLZ02001 |
All cab, box and SUV configurations covered. Drop-In systems are plug-and-play filtration upgrades and are not compatible with fuel sump kits.
Already Own a Drop-In Module?
Each kit here is the DIFSL5P2001 Drop-In module paired with an application-specific LZ0 adapter. If you already have the module, buy the adapter on its own:
- LZ0ADPT1001 — Adapter Kit for Silverado 1500 / Sierra 1500
- LZ0ADPT2001 — Adapter Kit for Tahoe, Suburban, Yukon & Escalade
Reliability, Simplicity, Protection
- Seamless integration. Works with the factory fuel system on GMC, Chevrolet and Cadillac applications.
- Injector protection. Can triple the life of your injectors and injection pump — no small thing on an engine running a Denso HP5 at up to 36,260 psi.
- FASS filtration. Optimizes combustion, restores horsepower, maximizes MPG. Results vary.
- Limited lifetime warranty. Register your FASS system for coverage.
Advanced Filtration Technology
- 2 micron absolute microglass filtration. Catches debris the 5 micron OEM filter passes straight through to your injection system.
- Extreme Water Separator. Third-party verified to remove over 99% of free and emulsified water.
- Air and vapour removal. FASS's patented process strips the entrained air and vapour that damage injection systems.
Key Benefits
- Improves reliability. Potentially triples injection system life.
- Maximized horsepower. Improved fuel atomization and restored timing.
- Optimized MPG. More efficient combustion. Results vary.
- Peace of mind. The Extreme Water Separator is a genuine fail-safe if you ever pull a bad tank of fuel.
- Cold weather confidence. Dependable starts in extreme cold.
- Cleaner operation. Fewer DPF regens and less soot.
- Improves fuel lubricity by at least 10%.
Key Features
- The only drop-in 3.0L Duramax filtration system that retains the OEM water-in-fuel light
- The only drop-in 3.0L Duramax filtration system with air separation
- 100% drop-in installation — no drilling, no modifications
- Retains the factory in-tank lift pump
- CNC-machined 6061-T6 billet aluminum dual filter housing
- Performance Radius Cuts (PRC) for smoother internal fuel flow
- Heater options available for cold weather
- Limited lifetime warranty with registration
- Engineered, manufactured and assembled in the USA
What's Included
- (1) FASS Drop-In Series air separation / filtration system
- (1) FASS XWS3002 Extreme Water Separator
- (1) Installation kit with all necessary hoses, fittings, bracketry and hardware
Recommended Add-Ons
- FASS Billet Fuel Filter Cap — upgrade the OEM plastic filter housing cap
- FASS Connect — monitor filter life and system status
- FASS Filter Pack — get ahead of your next service interval
- FASS Heater Elements — defy cold-weather gelling
Why FASS
FASS designs fuel systems around longevity, real-world performance, and ease of installation and service. The Drop-In Series delivers proven filtration and injector protection without altering the OEM configuration — the right call for daily drivers and work trucks alike.
Register your system with FASS to activate the limited lifetime warranty.
