Product Description
Unlock cooler EGTs and quicker spool on your 2004.5–2010 Duramax with the MBRP GMCA424 3" Turbo Downpipe. This Armor Lite (black-coated aluminized steel) pipe replaces the restrictive factory unit between the turbo and exhaust system to improve flow, response, and sound—while retaining factory mounting points for a clean, bolt-on install.
Fitment
- 2004.5–2005 Chevrolet Silverado/GMC Sierra 2500HD/3500HD 6.6L LLY (early 2004 excluded)
- 2006–2007 Chevrolet Silverado/GMC Sierra 2500HD/3500HD 6.6L LBZ
- 2007.5–2010 Chevrolet Silverado/GMC Sierra 2500HD/3500HD 6.6L LMM
- Direct-fit, bolt-on replacement between turbo outlet and exhaust system
Features
- 3" mandrel-bent tubing for reduced backpressure and improved turbo response
- Armor Lite black-coated aluminized steel for durability and heat retention
- Uses OEM-style flanges and brackets for straightforward installation
- Designed to complement MBRP downpipe-back/cat-back systems for LLY/LBZ/LMM trucks
What’s Included
- MBRP GMCA424 downpipe assembly
- Installation hardware as supplied by MBRP
Install Notes
- Allow penetrating oil time on turbo fasteners before removal
- Verify model year break—early 2004 LB7 is not compatible
Cross-Reference / Alternatives (MBRP-Only)
- 2011–2015 Duramax (LML) version: MBRP GMCA427 3" Turbo Down Pipe (CARB EO D-763-2)
- Alternate listing for the same LML application: MBRP GMCA427 3" Turbo Down Pipe – LML
- MBRP Exhaust Tips to finish the system:
FAQ
Is this downpipe CARB compliant?Yes—GMCA424 is part of MBRP’s 50-state legal lineup under CARB EO D-763-2 for the listed LLY/LBZ/LMM applications.
Does it require tuning?
No tuning is required. This bolt-on part is designed to work with the stock turbo and factory emissions equipment for the covered years.
Will it fit my early 2004 (LB7)?
No. Early 2004 LB7 models are excluded. This pipe fits 2004.5+ LLY, plus LBZ and LMM.
What systems pair well with this pipe?
Pair it with your preferred MBRP LLY/LBZ/LMM exhaust and finish it with an MBRP tip like the T5187 or T5188CF (linked above).
