Rear seat belts and fuel tank

[Bigsyke]

S14;

Does anybody know if the fuel tank is directly underneath the rear seat belt holes (middle two, not the seat belt buckles, but the bolts that secure that seat belt strap to the chassis - closest to the fuel pump).

I removed the rear seat belts, reinstalled the bolts, but heard a crack. Couldnt really see down the threaded bolt holes on the chassis to see if the plastic fuel tank was right below.

Now after that im getting horrible gas mileage. Just want to make sure I didnt crack the tank.

Also when I go to remove my gas cap, I it doesnt seem pressurized.