Desperate sensor advice please!!
 

Can anyone help?? Whilst fitting a decat uppipe typically a sensor broke! Its the one at the bottom of the standard uppipe, firstly what is its purpose? is it an oxygen sensor? Secondly im having a remap on tues, will i need to have it replaced by then? Would the sensor be cancelled out and be obsolete after the map? Car is a 2oo5 WRX
Thanks for any help and advice :)