closed loop is disabled because of this issue. every time I enable closed loop things go down hill fast. WB says 14.7 and the NB shows blm of 145 and starts dumping fuel. I've replaced the stock sensor twice with the same results. from what I read this should not be affecting a heated O2 enough to cause this. I just pulled the truck off the lift after searching for evidence of an exhaust leak and nothing. just for grins I am readjusting the valves once the engine cools. I just don't understand.