Help Me Interpret These Live Readings O2 sensors

[MH_Stevens]

My 2003 100-LC (260k miles) is only getting 7 mpg and has the "lean bank 2" code so suspecting bad O2 sensors I get this live data but I do not know how to interpret it.
O2S B151 low V .400
O2S B151 High V .500
V=1.275

O2S B251 LowV .400 - High V .550
B252 1.275V

Is this enough info? Does one need more data? If so I'l re read.

Thanks