WCFAB 2017-2019 L5P Duramax Passenger Side 3.5" Intercooler PipePowdercoat colors can be found here! The 3. 5" High Flow Passenger Side Intercooler Pipe for 2017 2019 L5P Duramax replaces the factory plastic two piece pipe with a high flow, 14 ga. aluminum one piece 3. 5" pipe. This part uses a CNC machined flange with a double o ring seal and an upgraded silicone boot in order to withstand higher boost pressures than the factory components to increase reliability and eliminate blown factory boots and horsepower