Hey guys just bought an 05 GT that came with a tuner and am just trying to figure a few things out. How can I tell what octane gas to be running in it with the current tune? Also can I turn the rear o2 sensors off myself and not affect anything else on the tune? The car runs great and do not want to mess it up. The car has full Kooks T exhaust with an ORX and just want o make sure it is not reading the rear o2 sensors. Thanks in advance!