Hilux 2013 3.0 D4D - P0031 Fault Code

[ToyotaHilux2020]

Hello,

first post on here, I've got a 2013 Hilux 3.0 D4D that has got engine warning lights on.

I've plugged it into techstream and it is showing P0031 - Bank 1 Sensor 1 AF Sensor.

I can't seem to find this sensor, does it have one? If so does anybody have a part number?

If not what else could this code indicate?

Thanks a lot in advance.

[rameshhelp]

Oxygen Sensor

[hiluxxury]

Do you have any more info? Done any work to it recently?