generally once 2minutes has passed after startup and temps above 140 it should go into closed loop , keep in mind the tt chip is open loop idle
there really isnt anything else to prevent it from going closed loop
if the o2 and is below 450mv its seen as lean (lean flag on) if it goes above 450mv rich flag is on , if it attempts to add fuel to get nthe o2 over 450mv and it doesnt cross over the 450mv point flip flopping rich/ lean as it should in closed loop it will look as if its in open loop