MBRP 4" XP Series Downpipe-Back Dual Exhaust Stack System S8000409

2001-2007 GM 6.6L Duramax LB7/LLY/LBZ
MBRP Performance Exhaust
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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.   

MBRP Downpipe-Back Dual Smokers
The down pipe back type system mounts to the short stock down pipe in Duramax equipped vehicles and eliminates the catalytic converter. The objective is to provide the absolute lowest exhaust gas temperatures, maximum exhaust flow, torque and horsepower possible. It's the ideal configuration for off road applications.

The Best Systems Start with the Best Materials

If what you want is a durable performance exhaust system that will not let you down then MBRP's XP Series is for you. Over 80% of the drivers on the NHRDA drag race circuit choose MBRP products to give them the winner's edge. Sixteen gauge T409 stainless steel stands up to anything the road can throw at it. We are so sure of this product that we back it with a Lifetime Warranty.

Built to Perform
You count on your truck to tow all of your gear to where you want it. With your MBRP performance exhaust you can make that happen with up to18 HP more horsepower and 28 ft/lb more torque. Give your truck more pulling power and much improved throttle response with an MBRP diesel exhaust system. Our systems are so much more efficient, it will be easy to see what your truck can really do.

Minimize Backpressure

The secret to getting more out of your diesel engine is to give it lots of cool, clean air. The only way that you can get fresh air in is to get the hot air out. From the spiral louvered high flow muffler to the fully mandrel bent tubing to minimal bend degree angles, your MBRP performance system gets exhaust out fast. Drop exhaust gas temperature by up to 200ºF and set the stage for all the performance you want. An MBRP performance exhaust system is the starting point to getting the most from cold air intakes, programmers, modules and downloaders.

Sound & Style

Performance is one thing but at MBRP we believe that appearance and sound is just as important. Every MBRP performance exhaust system has been specifically tuned to get the optimal sound from your pickup. With our unmistakable styling, there's no question that you have the hottest exhaust on the road - MBRP.


  • 4" T409 Stainless Steel Construction
  • Downpipe-Back Stack System
  • Stack Tips Sold Separately
  • Lifetime Warranty

Fitment Note: The MBRP Stack Plumbing is designed specifically for MBRP stack tips. This single stack pipe has a 4" OD outlet (where stack tip attaches). If you are not using MBRP stack tips, please use the measurements provided to confirm your stack tip will fit the MBRP plumbing.

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