So I dropped some Rush 2.0 slip ons last week. Didn't remap the EFI (which I am trying to avoid doing due to the high cost). Next I want to put a Arlen Ness Big Sucker on. (I hate the ham can look) I talked to a mechanic this week and he said that the EFI in the newer Sportsters will adjust itself as long as you don't replace past the 02 sensor, which I am not. He said I can put the BS on it no problem. My question, is has anyone done this? And if so what are the results? I have read that the efi in the sportsters does readjust itself when it sense less back pressure and more airflow and I have had a few mechanics tell me I don't and a few tell me I do. So which is it?