My dad is having the tank replaced in his 96 and a new fuel pump assembly. The mechanic called, says he needs a small electronic switch thats on top of the tank as its so rusty it will not come off without destroying it. mechanic said it was $140 Is it just to turn the CEL on when the fuel cap is left off? what is this called? what does it do? Can you live without it? Also the mechanic says that he cannot get the filler tube off the tank. agan becauce of rust. Is it possible to just cut the rubber hose and clamp it on to the new tank? Does the special fitting holding it (and the vent tube) on have a purpose? Thanks guys!