What would cause shortness of breath and pain in left breast chest CT scan normal X-ray normal abg normal EKG abnormal oxygen saturation normal?

It may be the heart! You need to have your heart checked by a good cardiologist. The best test for you is a session of multifunction cardiogram. It is accurate, affordable and stress, drug and radiation free! good luck! http://en.M.Wikipedia.Org/wiki/multifunction_cardiogram.