My fuel gauge Keeps spazzing out from empty to however much gas I have in the tank. What part do I need to get?

 

im not 100% sure but i think the sender and pump are all in one in the tank on a 98,.You could try and put some dielectric grease on the pump connection and if thatdosent work your sender is probaly bad.i have a 97 and ine was doing the same thing...io had to buy a new pump. a little of advise when it comes to fuel pumps splurge and get an oem pump the aut parts store brand airtex suck.I went threw 3 and then i got fed up and bought an oem pump.And you have to drop the tank to replace it unless you cut a hole in the cargo aera right above the openning on the tank.