then do a couple of sweeps as it accessed the O2 sensors then it would bump the short term fuel trim up a lot. Would end up around 13 afr ratio at idle and never change until the engine was sped up. Then the short term trim would drop back down and I would get normal readings until the next time it went to idle and it would do the same thing again. I got sick of it and just deleted the narrow band O2 sensors. It took a little time to get it tuned with the wideband but it works great now. I could never find a way to completely shut off the feedback at idle.