89CAL

hi mate just got a couple of questions about aem wideband i got mine today and i welded in the bung and got the gauge in the spot that i wont it but do i have the sensor in our out of the bung when i turn to accessories to   calibration it? and second question where do u get power source for the gauge ? some people say radio , cigaret light or do u get its own power and does it have to have power all the time