tricky o2 problem

Code 141 (o2 Heater)indicates o2 sensor was bad I replaced it and the other aft as recommended. Check engine Light came back on. Checked to see if ignition on heats up sensor and it does all except the one which created code. Checked volts going to o2 sensor the two new ones. The one working is 12 volts the one still not heating is 10.5 volts. Any suggestions how to fix this? All imput appreciated.

Thanks

Checked both sensors the units are fine. There is not enough volts only 10.5 going to the one to activate it. Any ideas?? where does wiring route from sensor to where? Strait to fuse?? can anyone help??