i eraced the codes yesterday the only one that has came back as of today is the p1870 or the trans one. Is there chance that the relearn code was thrown from the last motor that was put in it cause the guy that we got the truck had just put a lkq engine in it and water in it and it froze and cracked the head so thats when we got it and put our 05 5.3 in it. Or does every motor put in it have to be relearned??