One of this week's to-do items was to figure out why my gas gauge is dead. Suspect #1 was the fuel level sender, parked over the gas tank. Toyota engineers very politely gave us an access hatch through the floor of the cargo area. God bless 'em, and mine was a refreshing perfect medium blue. But the bolts are impossible to turn and one appears to be fairly corroded. I've been applying PB Blaster each day and working them gently, to no avail. We're preparing to heat the area with a hot air gun to do the "heat/beat/repeat" approach to things, and we have an impact driver in reserve as another trick. But given this whole area is directly above the fuel tank, we really don't want to get too rowdy with it. Any suggestions for how to get that hatch off?