i say no... of course without them u will have the check engine code, ive also been told that your car will run worse without but mine seems to be fine without :dunno:
I'm going to have a set of Steeda Mils for sale in a few weeks...i will only need them to pass inspection then i'll take them off and load my tune from my Xcal after my blower is on...So if your interested in a 1 hour used set of Mils let me know.
I have Steeda MIL Eliminators, they work fine and really do nothing more than send the correct voltage to the ECU to tell it that the rear cats are functional even though there aren't even there on my exhaust system. So, I really don't see how taking them off once they are on will help performance or MIL illumination unless you can program your ECU to ignore any signals from the rear O2 sensors.
no you don't the rear O2's only have 2 funtions, exhaust temp and as a cat sensor They will not affect your performance at all without having mil's