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USD 144.99
Part #: MBGMAL401

MBRP 4" Aluminized Front Pipe GMAL401

2001-2005 GM 6.6L Duramax
Part #: MBGMAL401
★★★★★ ★★★★★ 2 Reviews
$ $144.99
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XDP - MBRP Authorized Online Retailer XDP is a MBRP Factory Authorized Online Retailer ID# 600207727. We would like you to shop with confidence knowing your purchase is covered by the manufactures warranty.   

Get even more exhaust flow with this 4" MBRP Front Pipe w/ Flange.

MBRP Front Pipes are jig manufactured to ensure total accuracy. Smooth mandrel bends will give you the best flowing Duramax Front Pipes in the industry. Gain extra power and enjoy the EGT reduction as well. Constructed from heavy duty aluminized steel you can count on this pipe lasting for years to come.

  • 4" Aluminized Steel Construction
  • Increase Power & Efficiency
  • Lower Exhaust Gas Temperatures
  • Mandrel Bent & Jig Manufactured
  • 3 Year Warranty

Will work on but is not recommended for the 04.5-05 Duramax LLY with out the use of aftermarket tuning to eliminate EGR codes.


  • MFG. Number GMAL401
  • Manufacturer Name MBRP Inc.
  • Shipping Weight 14.00 lb.
  • Shipping Length 52 in.
  • Shipping Width 9 in.
  • Shipping Height 15 in.
  • Fuel Type Diesel
  • UPC 882963100634
  • Warranty Yes
  • Warranty Info 3 Year
  • Prop 65 WARNING: Cancer & Reproductive Harm -


★★★★★ ★★★★★
5.00/5 Stars out of 2 Reviews
best investment ever
Anonymous (Unknown) | August 23rd, 2007
Guys i just got my pipe today and put it on.. all i can say is wow with my boost controller and other mods that turbo whisles now. this is probably the best thing i have put on my truck yet.
Lewis (Shelton) | September 17th, 2012
I purchased this a few weeks ago and have had it on since. It made a big difference in power and sound. The turbo whistle is quite a bit louder. The fit was really good. Came with new hardware and a gasket. Love it, now I just need to change out my 4 inch Flo-Pro with muffler for a MBRP 5 inch straight pipe.

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Questions and Answers

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Most Popular Questions

Does the front pipe come with new bolts for the exhaust flange and a gasket?
View Staff Answer 
Yes, this pipe comes with new hardware and a gasket.
does this replace my cat section of pipe on my lly. I have their cat back exhaust now with stock down pipe
View Staff Answer 
The MBRP 4" ALUMINIZED FRONT PIPE GMAL401 will replace the factory front pipe on the truck. The front pipe is where the factory catalytic converter is located.
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.