Land Rover Repair: 2000 Land Rover Disco II troubleshooting codes, o2 sensors, sensor circuit

Question
I'm having trouble finding the definition of 2 troubleshooting codes- I hope you help. I think they have to do with the O2 sensors. The first code is P0134 and the second is P1170. Any ideas? Thanks for your help- Valerie

Answer
P0134     O2 sensor circuit no activity detected (bank 1, sensor 1)     Front sensor LH bank open circuit.

P1170     Downstream fuel trim malfunction (bank 1)     Front sensor aged - rear HO2S adaption too lean/too rich LH bank (NAS and EU-3 only)

I would recommend replacing both of your upstream O2 sensors.