Going to finally drop in an off road xpipe with (no cats) with 02 bungs on my 01 GT. Currently running a tune with the factory cats. Do I need to pick up a set of MIL eliminators for the front and back O2 sensors or just get an updated tune to turn off the O2's and specify I'm running an off road pipe will work? Would that hurt anything as far as fuel/air ratio (not sure how that works). Also as an FYI, the car is emissions exempt at the moment and hopefully will be moving forward.