Lambda faulty?

[scouseeric]

Drove through a pool of water this morning and my mil lite up straigt away.
Hooked up the scanner and it cleared 2 out of 3 faults.
mil now off but the one fault remaining is a high volts reading on the post cat lambda. I have tried a battery off reset but no change .The voltage reading in the live data is steady on 1.25v and the o2 moves accordingly with the revs.Any clues or is a new sensor the answer?

thanks chaps.

PS. the 2 cleared faults were lean mixes banks 1 and 2. an lpg quirk im
suffering with now and then.