i've done both... actually the tranny fluid was low when i got it but didn't know untill i got down the street, so i fixed that put some more fluid in it, but the rattle is still there, and yesterday afternoon the check engine light came on and i got it checked out it came up something to the effect of evap. valve clogged or something like that, but it was speaking of the gas tank, and i noticed while i was under there looking that the hose connecting the fill port for my gas tank and the gas tank itself was dry rotted and had cracked on the top side, so i have to get another one of those... i was kinda wondering why i smelled gas almost everytime i got out of it, lol...