Gone into limp mode due to o2 sensor fault

Hi guys,

Twice in the past week, my car's gone into Limp mode when accelerating above about 55mph, citing an issue with the o2 sensor bank 1 according to the scanner.

Each time, turning the engine off, waiting a few secs and then turning it back on has cleared it and it's gone back to normal. I had a full day of normal driving between the two instances.

Does anyone have any ideas why this is likely to have happened?

Also, my octavia's a 2013 2.0TDI SE... it has generally only been used for short runs recenlty due to a change in working patterns so I know it needs a good run at speed to help the DPF out, could that be linked?