Wehrli 2020-2026 L5P Duramax 4" Intake Kit with Air Box Stage 2
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.
The factory intake on a 2020-2026 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax L5P is restrictive plastic from the fender to the turbo. The Wehrli Stage 2 4" Intake Kit with Air Box (Manufacturer Part # WCF100684) replaces the whole path — 4" fabricated aluminum pipe, a 4" intake horn with PCV port and surge ring, and a sealed 10 gauge air box that seals to the functional ram air port in the hood. Bolt on, no tuning. One setting must be changed before you start the truck — see Notes.
Why Choose the Wehrli Stage 2 4" Intake Kit?
- Includes the intake horn – this is what separates Stage 2 from the standard kit. The horn is over an inch larger than OEM and removes the restriction sitting right at the turbo inlet.
- Seals to the hood ram air duct – the kit ships with the seal for the functional ram air port, so the box draws cold air from the hood duct and the inner fender instead of underhood heat.
- 4" aluminum piping – large diameter with smooth aerodynamic bends, improving intake air velocity and volume.
- 10 gauge aluminum box and lid – the lid element lifts off for a filter check without pulling the box apart.
- Dry filter with an Outerwears cover – hydrophobic pre-filter keeping water and grit off the element.
- More sound – a noticeably more aggressive engine and turbo note under acceleration.
- Custom powder coat – the whole assembly in your choice of Wehrli's colors. Made in the USA.
Kit Includes
- 4" intake pipe, fabricated aluminum
- 4" intake horn with PCV port and surge ring
- Air box and lid, 10 gauge aluminum sheet
- Dry air filter
- Outerwears pre-filter cover
- Seal for connection to the functional ram air port on the hood
- High quality silicone boot and stainless steel T-bolt clamps
- Installation hardware
Installation Highlights
Installs easily with basic hand tools and needs no tuning — it fits a stock truck with no other modifications or upgrades necessary. Disable the air filter monitoring system before the first start.
Fits These Models
2020, 2021, 2022, 2023, 2024, 2025 and 2026 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax L5P.
Specifications
- Intake pipe: 4" diameter fabricated aluminum
- Intake horn: 4" with PCV port and surge ring, over an inch larger than OEM diameter
- Air box and lid: 10 gauge aluminum sheet
- Filter: dry element with Outerwears hydrophobic pre-filter cover
- Replaces GM part numbers: 84841229, 84841225, 84262962, 85614333, 84554702
- Shipping weight: 21.0 lbs
- Package dimensions: 20" W x 18" H x 20" L, ships in its own box
- Finish: custom powder coat, color selected above
- Made in the USA
Key Features at a Glance
- Intake horn included - the Stage 2 difference, an inch larger than OEM.
- Hood ram air seal included - real cold air, not underhood air.
- 4" fabricated aluminum - replaces the restrictive plastic tract.
- 10 ga. sealed air box - serviceable lid.
- No tuning required - bolt on to a stock truck.
- Custom powder coat finish - pick your color above.
Notes
- ⚠ Disable the air filter monitoring system before initial start up. Wehrli is explicit: skip it and the truck throws a SERVICE AIR FILTER message that requires a dealership to reset. When the setting is correct, air filter life reads as disabled.
- Lead time varies by color. WCFab Red, WCFab Grey, Candy Teal, Gloss White and Gloss Black are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- Wehrli also offers this truck's charge piping separately — call if you want the full Stage 2 bundle with intercooler pipes.
FASS SKU: [ADD FASS SKU]
Manufacturer Part #: WCF100684
Questions? We’re Here to Help.
Have questions about upgrades for your 6.6L Duramax L5P? Contact FASS Motorsports and we’ll get you dialed:
Phone: 636-429-7020
Email: info@fassmotorsports.com
This part fits the following vehicles:
| Years | Make & Model |
|---|---|
| 2020 | Chevrolet Silverado 2500 HD |
| 2020 | Chevrolet Silverado 3500 HD |
| 2020 | GMC Sierra 2500 HD |
| 2020 | GMC Sierra 3500 HD |
| 2026 | Chevrolet Silverado 2500 |
| 2026 | Chevrolet Silverado 3500 |
| 2026 | GMC Sierra 2500 |
| 2026 | GMC Sierra 3500 |
Fitment is listed by year, make and model. Some applications also depend on cab, bed, drivetrain or engine — if you are not sure, call 636-429-7020 or send us your vehicle details and we will confirm before you order.
