I see where Danny is going with this... incorrect diagnosis to begin with
(Either that or someone has stung you for a sensor that they never fitted).
Check the condition of the wiring to the H02 sensor as it's close to the exhaust and so susceptible to damage - this is the cause of a lot of so called
"Lambda sensor faults" rather than the sensor itself.
To me, from what you've said the H02 sensor could indeed be the fault but so could the coolant temp sensor... misfiring, increased fuel consumption. It needs looking at by someone that know's what they're looking at when presented with the live data screen. Code reading is only half the battle
Mink