Hi Al
Mine has been down to as low as 0.3 On low tickover at MOT with the old engine
Are you still running the air bypass valve? I don't use one, but what does quite often move is the throttle position sensor values. Resetting the throttle closed and wide open positions usually aligns things back up to match the map back to the actual throttle position But why bank to bank would be different not sure - from recent info check cams are still all lined up!