Technical P0130 code

[roberthall]

Hi. We have a 2012 Fiat Ducato X250 2.3 multijet Autotrail Comanche with 23000 miles on the clock.. I've had P0130 code come up a couple of times. I can clear it but it comes back on at a later stage. Could be a few runs out or more. P0130 reads O2 sensor. Is it the O2 sensor or could it be something else? How common do O2 sensors go duff? Where is the 1st O2 sensor? Any help greatly appreciated.