An LMM PCV reroute fix is a simple crankcase ventilation modification for 2007.5–2010 6.6L Duramax diesel trucks. It is designed to reduce oil vapor buildup in the intake system by redirecting crankcase gases away from the turbo inlet and intercooler piping. On the factory LMM setup, the PCV (positive crankcase ventilation) system routes oil mist back into the intake. Over time, this can...