Truck noris cam, running 5% @ idle -Ecm adding fuel

Ok fellas got a head scratcher.

got a 03 5.3 DBW truck with a truck Noris cam. Speed density set up, dialed in open loop at idle, cruise and WOT. AFR on both banks is 1.0LA (while in open loop) I have a wide band in both banks for tunning purpose. Once I get into closed loop my AFR gets 5% rich on both banks (idle only, move into gear and La is at 1.0) My commanded LA is at 1.0 (14.68) no matter what tables I adjust I can’t get the ecm to stop adding fuel. The ecm is doing its job but the oxygen sensors are telling the ecm to add fuel. That leads me to believe there is unburt oxygen in the exhaust. I have no miss fire codes, cylinder temps seam low but all stable and relative to each other. I have installed a new o2 sensor no change. I have had injectors tested and have checked for vacuum leaks can’t seem to find any. Don’t hear or feel any exhaust leaks. What am I missing ?