Okay gentleman I have a 2007 GMC Sierra 1500 with the 5.3 vortec it has a serious oil leak looks to be coming from the passenger rear side I already changed the valve cover gasket it's not that I checked the crankshaft sensor not that it only seems to leak when it's driving it doesn't seem to really leak out a lot when it's just idling any ideas I've heard about the oil pressure sensor when I fell back there that seemed more dry than it would be if it was that. Also tried uv dye and like I said it leaks while driving so when i stoped to look with light oil is everywhere. Will add pics later today.