Civic EG

My gas gauge keeps telling me i'm out of gas when I still have about 2-3 gallons left. It ran out today and when I filled it up it still apparently had 4 gallons in it. Is there a sensor I need to replace? (Sorry if searching would solve the problem, but I'm at school right now )

it could be the sending unit in the tank or the guage cluster...

my gas gauge do this weird thing to, but mine is like when you turn left it goes down...lolz idk if its the floater inside the gas tank?...any thoughts...

Mine sucks too. It takes forever to go up and down. I'm just swapping in a new cluster though