approximate cost to replace oil pump 2007 GMC 2 wheel drive 6 cylinder.

It is ‘quite’ possible this problem is a malfunctioning oil pressure sending unit (switch) .. The 4.3L V/6 isn’t know for actual oil pressure problems. I highly recommend having the oil pressure tested using a manual test gauge before contemplating any repair solutions.. IF test results indicate oil pressure is indeed low - continued operation MAY damage engine. Good luck!