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Part #:

AFE 49-44059 Large Bore HD 4" Downpipe-Back Exhaust System

2001-2010 GM 6.6L Duramax (Crew & Ext. Cabs)
Part #:
FROM 584.25
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The AFE 49-44059 Large Bore HD 4" Downpipe-Back Exhaust System for your 2001-2010 GM 6.6L Duramax is engineered to perform in the most extreme environments. This system is constructed from 4" mandrel bent stainless steel tubing for maximum flow increased horsepower, increased torque and lower EGTs. This system uses high quality band clamps, OE-style bayonet hangers and includes an adjustable hanger clamp for a tight secure fitment. This system is includes a free-flowing 24" long muffler and includes your choice of a 6" diameter polished stainless steel or black coated clamp-on exhaust tip.

Installation is a Snap:
This Large Bore HD System Includes an extension pipe and an adjustable hanger for a perfect fit. This kit uses factory mounting locations providing stability and hassle-free installation.

Leak-Free Seal:
High quality OE style flange and band clamps are used for a complete 360 degree sealing surface.

Aggressive Sound:
A free-flowing 24" long muffler is used to absorb high pitch tones producing a powerful sound and unleashing all available horsepower and torque out of your rig.

OE Fit:
OE style bayonet hangers are used to maintain a stable pipe location during high vibration and high heat conditions. The Bayonet tip holds the hanger bushing in place for an OE style fit that does not change with time. 

Flow and Performance:
This Large Bore HD exhaust system is constructed of 4" mandrel bent stainless steel tubing for maximum flow. Smooth transition bends allow for low turbulence, increasing horsepower, torque and lowering EGTs.


  • Adjustable Hanger To Fit 2001-2010 Models
  • 4" Mandrel-Bent Stainless Steel Construction
  • Your Choice Of 6" Polished Or Black Exhaust Tip
  • Free-Flowing 24" Muffler For Deep, Powerful Sound
  • Uses Factory Mounting Locations For Hassle-Free Installation
Fitment Note: Fits Crew Cab/Short Bed, Crew Cab Long Bed, Extended Cab/Short Bed, & Extended Cab/Long Bed

Warning: On 2007.5-2010 models, this free-flowing race exhaust requires the use of an aftermarket performance programmer with off-road tuning.

Product Options:
49-44059-P - Polished
49-44059-B - Black


  • Manufacturer Name AFE
  • Shipping Weight 82.00 lb.
  • Shipping Length 60 in.
  • Shipping Width 14 in.
  • Shipping Height 19 in.
  • Warranty Yes
  • Warranty Info 2 Year
  • Prop 65 WARNING: Cancer & Reproductive Harm -


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Emissions Notice

This product is not legal for sale or street use in California. Certain aftermarket products are subject to governmental emission standards regulated by the California Air Resources Board. In order for these products to be legal on a specific vehicle in California, the part number must receive a CARB Executive Order (EO) number. This number makes the part legal for use only on specific years, makes and models of vehicles. A decal with CARB EO number for these parts must be displayed in the engine bay to satisfy smog inspection requirements.