03: This manifold houses the factory oil cooler, a few sensors, and the factory oil filter. The black tube is what the factory drop-in filter surrounds and attaches to. Atop the tube is a bypass valve that is famous for breaking. When it does, oil completely bypasses the filter and sends contaminants straight to the high-pressure oil pump (HPOP) and injectors. This is the last you’ll see of this manifold. It will soon be replaced by a new Bulletproof Diesel part.