Diesel Fuel Rail Plug for 2007.5-2012 6.7L Dodge Cummins and 2004.5-2010 GM Duramax Maintains proper fuel rail pressure under heavy acceleration/engine loads Highly reccomended for race/modified engines! Helps eliminate low fuel rail pressure DTC Codes P1093 and P0087 Fits 2007.5-2011 Dodge 6.7L Cummins and 2004.5-2010 GM 6.6L Duramax Eliminate leaky/weak fuel rail relief valves