The factory LLY/LBZ/LMM down pipe makes an abrupt directional change immediately after the turbine flange, which restricts exhaust flow and impedes performance. Additionally, the indentations in the piping further obstruct exhaust flow.

Upgrade your Duramax with the PPE Free-Flow Downpipe and eliminate the rusted, restrictive factory design. The PPE Down Pipe highlights unrestricted 3-inch diameter flow path all-along, cast stainless-steel upper and lower flanges with CNC machined mating surfaces, and three-inch 304 stainless steel mid-section. It ensures smooth transitions for unobstructed exhaust flow. To further enhance performance, it comes with a woven titanium sleeve that effectively insulates heat, protecting the engine bay.

OEM P/N for reference: GM 98050150