First time posting here; looking forward to great responses! I have a 2007 FLHX that I bought used in '13. Had 3900 miles on it, been modified with Screaming Eagle heads, 2-1 exhaust and a Power Commander III. Here's my question(s): I'm putting true duals and V&H long shots on it and need some guidance on whether or not to connect the O2 sensors back up and tune it. What's the advantage of closed loop tuning with the sensors hooked up? They are not connected currently.