currently none of my O2 sensors are connected..im pretty sure. i know the rear one are just zip tied up (previous owner chopped up the exhaust). i have to pass emissions to register my mustang..if i get a pair of the just the rear O2 sensors and buy some eliminators to trick the ecm will that turn off my MIL light? i plan on redoing exhaust from mid pipe back with off road stuff..should i get the pre cat sensors hooked up too or do they even matter? basically from manifold im thinking mid-pipe pre cat senors hooked up, post cat sensors with eliminators tied up out of the way and exhaust run to back, with mufflers of course. i guess my question is do you think this will work and i will pass emissions..they just plug up an obd2 to check codes