low oil isnt good. typically when the oil is on it means the oil pressure is 7 psi or less, not a good sign, keep that oil topped off. now if ur engine hasnt seized up on u. these problems could be several things going on. since the check engine is on get a obd 2 scanner check on it, autozone does that for free, or u can rent the tool and get all ur money back after u rent the tool. but it could be a nimber of things, clogged fuel filter/pump, fuel injectors, faulty spark plpug wires, spark plugs, maybe the engine is running too rich or too lean, etc, etc, the list goes on and on. theres alot of maintenance that goes with cars, theres a reason why theyre so expensive. a scanner would be the most useful tool for you, as it will list the most probable cause.