2020-2026 L5P Duramax Stage 3 High Flow Intake Bundle Kit

Stage 3 for 2020–2026 L5P Duramax HD is Wehrli’s full street-legal airflow package: the Stage 2 intake and intercooler pipes plus a 3.5" ceramic-coated, heat-wrapped DOC-back downpipe. It opens intake and exhaust flow while connecting to the DOC outlet flange and mating to the OEM front pipe with sensor bungs — factory emissions equipment stays in the system.

What you get: everything in Stage 2 (4" intake/horn/air box, 3" hot / 3.5" cold IC pipes, boots, clamps, hardware) plus the 3.5" DOC-back downpipe with OEM sensor bungs and 4-bolt flange. Bolt-on; no tune required on a stock truck. Bundle saves vs buying the pieces separately.

Wrong kit?

• No downpipe needed → Stage 2 WCF100414
• Pipes only → Stage 1 WCF100410
• 2017–2019 L5P → Stage 2 WCF100441 or Stage 1 WCF100718 (ask about Stage 3 for that year range)
• Cannot ship to California (manufacturer restriction)

Pairs best with emissions-compliant tuning and a drop-in turbo if you’re chasing more power. Powder lead times vary by color — see Availability. We can install in Idaho Falls when the bay’s open.

Call 208-542-7793 with year/make/model if you’re choosing between Stage 2 and Stage 3.

Emissions-compliant performance only — Powertech Diesel does not sell deletes or defeat devices. Retains factory emissions equipment.