Q: I need help with my fuel tank.

Replacement of the fuel tank involves more than just the tank as the fuel pump has to be carried over from the old tank to the new and there are high pressure and EVAP system connections that must be made. This is a job, too, where there is literally no margin for error due to the unique hazard that gasoline and gasoline vapors poses. And, once the job is complete, the acceptable amount of liquid or vapor "leakage" is zero. So, unless you are absolutely positive you can do the job perfectly this is not something you want to attempt on a DIY basis. Before replacing the tank, of course, you want to be sure that you do need a new one. Your car is only 7 years old and so it is somewhat unusual that it would need a new tank. If you are experiencing a leak, you could have YourMechanic perform a leak diagnostic and if indeed it turns out that you need a new tank, the Mechanic could at that point give you an estimate of the cost to replace the tank.