If I have no cats then do I need the mil eliminators? Can the o2 sensors be turned off in the ecm? Also can the other emissions stuff too with the ecu? Who can do that? does the ecu have to be flashed? or can it be a chip? On my mid pipe i have two holes on each side for o2 sensors but i have no cats.. why is that? What do most people do? Sorry these probably sound pretty easy but ...