Help! Car won't rev above 2000 and idle sounds like a cammed V8

[Clay]

So I'm trying to sell my Civic this mornkng so I go to start it to let it warm up and to fill it with gas. I turn the key and it sputters, I figure the gas is low so I put a couple gallons in and turn the key again. It starts but is all but dying. It sounds like it's missing on at least one cylinder too. I put my foot to the floor to see how it changes and the car won't even rev to 2000. Is this a fuel filter issue? Injectors? Coil packs? Anyone experienced this before?

Thanks in advance