GM Duramax LMM 4" Down-pipe Back Exhaust (2007.5-2010)
Type: Exhaust Systems | Fits: GM Duramax
Free your LMM Duramax with a 4β stainless downpipe-back race exhaust designed for maximum flow and competition performance.
The GM Duramax LMM 4β Stainless DPF Delete Exhaust System is built for 2007.5β2010 GMC Sierra and Chevy Silverado 2500/3500HD pickups. Designed for off-road and race use, this downpipe-back system eliminates restrictive emissions components, including the catalytic converter and DPF filter, to maximize flow, reduce backpressure, and improve fuel efficiency. With OE-style hangers for straightforward installation and durable stainless steel construction, this system is the go-to choice for enthusiasts who want serious performance gains.
Vehicle Fitment
- β 2007.5 GMC Sierra 2500HD/3500HD 6.6L Duramax LMM
- β 2008 GMC Sierra 2500HD/3500HD 6.6L Duramax LMM
- β 2009 GMC Sierra 2500HD/3500HD 6.6L Duramax LMM
- β 2010 GMC Sierra 2500HD/3500HD 6.6L Duramax LMM
- β 2007.5 Chevy Silverado 2500HD/3500HD 6.6L Duramax LMM
- β 2008 Chevy Silverado 2500HD/3500HD 6.6L Duramax LMM
- β 2009 Chevy Silverado 2500HD/3500HD 6.6L Duramax LMM
- β 2010 Chevy Silverado 2500HD/3500HD 6.6L Duramax LMM
- β Not compatible with Cab & Chassis models
- β Not compatible with late-model 3-bolt flange trucks
Specifications
| Feature | Details |
|---|---|
| Product Type | 4β Downpipe-Back Race Exhaust System |
| Tubing Size | 4β diameter |
| Material | High-grade stainless steel |
| Design | Straight-through, no muffler (optional 4β muffler available) |
| Configuration | Downpipe-back, removes Cat & DPF |
| Hangers | OE-style for direct factory-style fit |
| Bungs | None (bung-free design) |
| Application | Off-road/competition use only |
| Tuning Requirement | Requires custom race tuning |
Whatβs Included
- 4β stainless downpipe-back exhaust system
- OE-style hangers pre-installed
- Mounting hardware package
- Optional 4β muffler (sold separately)
Key Features
- Removes catalytic converter and DPF filter for maximum flow
- Built from corrosion-resistant 4β stainless steel
- Downpipe-back design for full system upgrade
- OE-style hangers ensure simple installation and secure fit
- Bung-free design optimized for performance applications
- Optional 4β muffler for reduced exhaust noise without sacrificing power
Benefits
- Improves horsepower and torque by reducing restriction
- Lowers exhaust gas temperatures (EGTs) for safer operation under load
- Boosts fuel economy with a free-flowing exhaust system
- Aggressive exhaust tone for a competition-ready sound
- Long-term durability thanks to stainless construction
Important Notes:
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Important Notices
- OffβRoad Use Only
Products sold by JS Speed are intended for offβroad use and may be illegal on public roads where emissions or pollutionβcontrol laws apply. - Check Local Laws
Before purchasing or installing, verify all applicable local, state/provincial, and federal regulations to ensure the modification is legal in your area. - Professional Installation Recommended
These parts should be installed by qualified professional mechanics. Improper installation can cause performance issues or vehicle damage. Unless a product page explicitly states otherwise, installation instructions are not included. Components are designed for users with solid mechanical knowledge, and minor adjustments or modifications may be required for proper fitment. Returns or refunds cannot be accepted due to difficulty completing an installation or the absence of instructions. - Warranty Impact
Use of these parts may void your vehicleβs factory warranty. Confirm with your vehicle manufacturer before purchase and installation. - Limitation of Liability
JS Speed is not responsible for damage, failures, or issues arising from the use or installation of these products. - Product Images
Images are for illustration only and may differ from the actual product due to manufacturer updates or improvements. - No Performance Guarantees
While these products are designed to enhance performance, JS Speed does not guarantee specific performance results.
