I have a 2000 Honda Accord LX 2.3L 4 Cylinder with about 160k miles. My issue is that sometimes after driving for a while, when I turn the car on again it'll have a weak start up and idle really low at about 500 rpm or sometimes it'll just shut off. Some times on cold starts it'll shake like mad until i shift into drive. I've changed the spark plugs, wires, belts, had the battery tested, used fuel cleaners, and changed the air filter but im still not sure why i get a shakey start up with really low idling. Any ideas?