I have a 2009 Sierra with Active Fuel Management. Driving into work this morning my low oil Pressure light came on. The dealer just called and told me that this is an issue with this engine and the fuel management. He said they are doing an initial repair involving installing a baffle in the oil pan, cleaning out the engine, and replacing some gaskets. All of this is drive train warranty work and if I have the problem again, they will do a more expensive repair involving rebuilding the engine. Has anyone else had this problem and what is the real issue?