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USD 144.99
Part #: MBGMAL401

MBRP GMAL401 4" Aluminized Front Pipe

2001-2004 GM 6.6L Duramax LB7
Part #: MBGMAL401
★★★★★ ★★★★★ 2 Reviews
Temporarily Out of stock - More on the way!

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The MBRP GMAL401 4" Aluminized Front Pipe is jig manufactured to ensure a perfect fit on your 2001-2004 GM 6.6L Duramax LB7. MBRP's mandrel-bend construction gives you smooth bends for enhanced flow. 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


  • 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 -


★★★★★ ★★★★★
5.0/5 Stars out of 2 Reviews
best investment ever
(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.
(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.
XDP continues to closely monitor the COVID-19 (Coronavirus) outbreak. As an integral part of the automotive supply chain, at this point all call centers and distribution centers remain fully operational to ensure we keep vital service components flowing to vehicles used in transport of goods and emergency response. To ensure the health of our employees, families, and customers, we have made the following procedural changes:

  • UPDATE: Effective 6/1 Customer Service resumes normal business hours of M-F 8:30 – 9:00pm EST.
  • Effective 3/18 we have decided to temporarily close both of our retail stores in NJ and NV.
  • Our technical sales team remains available Mon-Fri 8:30am-9pm and Saturday 10:30am-7pm EST.
  • All employees have been encouraged to follow the CDC's recommendations at home and in the workplace.
The circumstances of this virus are fast moving, as such, we will continue to update you with any further operational adjustments as needed. As always, we value your business and appreciate your patience as we manage this situation together.
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.