It seems to be a small leak but some of the oil is falling onto the exhaust tube directly below so not sure how much is burning off... The sensor I have is installed along with what appears to be a sleeve in the orginal sensor mounting hole on the side of the gearbox.
easiest to drain some tranny fluid out, remove bolt, remove sensor, fill gaps with tranny fluid proof sealant, and stick back together...and replace tranny fluid
I was asking what sensor typer because I have a very snug fitting plastic sensor like Milano