Just put a new set of V&H bigshots on my wifes 07' Deluxe. The plug to disconnect the rear O2 sensor is located attached to the bottom of the oil tank. Sombitch took me about twenty minutes just to unplug it so I could remove the old pipes. Add another twenty minutes to plug it back in. I hope HD isn't taking their design from the Japanese, I'll have to get smaller hands.
Yeah I know where that one O2 sensor is and if you reach underneath the oil tank and un clip it you can reach it real easy. It took me about five minutes to un clip it and then about a minute to take the clip apart. It is a crappy place
Well, I found that if you put one hand down the empty battery compartment; then one hand under the oil tank, grip both ends with the respective hands, then unclip the holding clip with the right hand's index finger's fingernail and pull at the same time with the left hand's connector; ................. it's a piece of cake to unclip them.