MBRP 2003-2004 Dodge Cummins 4 Down-Pipe T409MBRP 2003 2004 Dodge Cummins 4 Down Pipe T409 Some folks are just not satisfied with the usual. They have to always be pushing the limits; refining and adjusting; until they have the truck that has no limits. We have put together some components that will take you to the next level. The fastest path from the turbo to the tip is through an MBRP down pipe. Bulking up exhaust flow. Armor Plus Turbocharger Down Pipe; 4 in.; T409 Stainless; 4 in. Dual Wall