No 5v supply to Downstream O2s

2010 ACLB SR5 V6 4x4:
So I'm not getting a signal supply voltage to either of my downstream O2 sensors. If I'm reading the wiring diagram correctly, this 5v supply comes from the ECU and splits off to supply voltage to a few other sensors, like the mass air flow and coolant temp sensors, neither of which I'm having problems with. I don't see a fuse along the line anywhere that could be blown. Heater 12v is coming through fine on both.

I've visually traced the wiring harness as much as possible and can't find any damage. Is there something I'm missing?

Also the wiring diagram I have doesn't tell me how to identify which connector is which on the ECU (E5 vs E8), so if anyone has a diagram for that, it would be much appreciated.

 

The downstream O2 sensors generate their own voltage there is no reference voltage for an oxygen sensor, some vehicles use a bias voltage on the O2 circuit for circuit integrity detection but there's no 5v reference supply

What kind of problem(s) or code(s) are you having?