p1000, p0602,p0452, 02727

Hey everyone, Im having an issue with my 02 mustang gt. When I go to start it up it will crank and not start the first try, then the second try it is hard to start but it will start. After that it will run fine with no problems exept for a check engine light. After it has been ran for a little while it will start fine with no trouble unless it sites for more then half a day. Also sometimes after its hard to start when I FIRST take off it will bogg down with now power but only for a few seconds. But like I said after it has started it runs like a dream! When I pull the codes, these are the four that come up, p1000, p0602,p0452, 02727 All mods listed in my signiture. Thanks!!

After some extensive research I have found other people have had some of the same problems when they had a previous tune that did not get erased before getting a new tune. Does this sound right? is there some way i can remove the old tune that was on my preditor and reflash the new tune thats on my SCT livewire?