Car = 2003 Pontiac Grand Am 4cyl Ecotec. Fuel pump went kablooey and while changing it I also changed the fuel filter. On a lark I cut open the old fuel filter (OE ~ 90,000 miles) and it was black with what looks like carbon/charcoal. Could charcoal from the EVAP canister be finding it's way into the gas tank? Is this at all normal? GM says there is no maintenance interval for the fuel filter, replace as needed(!!). I have decided a 50,000 mile fuel filter change is maximum but if there is charcoal from the canister getting into the fuel tank maybe there is more maintenance I should do?