o2 sensor

alright help a mechanical shit for brains...what is the function of o2 sensor?...is it merely an emissions feature?...my question is this...i was thinking about trying an akrapovic mega phone for an r6...but in the mean time i want to see and hear if i like what it would basically be...so i want to remove the mid pipe and cans and run it like that for a week or so as a trial...this will mean disconnecting the o2 sensor...can i just move it out of the way?...i know i will prolly get a check engine light...but will my idea fuck up the bike in any way?...thanks in advance :smiley-asskiss: