While you might easily conclude that there are no differences between Episcopalian and Catholic-based on some things that are common to them, however, it is important to know that there are so many differences between the two, especially when you consider certain practices that are common to the two.
First, in Catholics, women are forbidden to be ordained as priests, whereas this type of practice cannot be found in Episcopalian. Second, catholic priests are not allowed to marry, whereas priests are very much allowed to marry in Episcopalian unless if a particular priest decides not to marry.
Episcopal Churches do not have a centralized system of leadership, unlike the Catholics that give the supreme authority to the pope or the Roman Catholic Bishop of Rome. Another difference is that in Episcopal Churches, Bishops are chosen by the people, whereas the appointment of a Bishop is made by the pope.