I didn't see anything that jumped out at me in the tune. Did you by chance cut wires for something else thinking you might never hook rear O2 sensors back up? I would think the easiest check now would be to check the resistance at the plug vs at the PCM.

 

What base tune (vehicle) is that OS for?

 

I didn't cut the wires. They have continuity from the sensor to the PCM connectors.

The tune is for a 2001 Silverado 5.3L. It was downloaded from EFILive.

Starting to think there is an issue with the PCM.

 

Segment swap back a 4l60e tune and see if they work

 

I'll flash in a 100% stock tune with 4L60E and try again tomorrow.

 

So I flashed in a 100% stock tune and am getting the same problem...

I have no idea where to go next.

 

Try a Spare PCM

If any of the NEW 02 Senors were not covered they could be bad. They typically have a cap or plug over the top of them so they don't corrode internally.

What Brand were the VatoZone sensors? I have had problems in the past and not just with GMs but other cars when not using Original Equipment brand 02 Sensors.

 

All three sensors (2 from eBay and 1 from Autozone) are Bosch 13474. All had caps and looked new and in good shape. I can't imagine that I got three bad sensors in a row.

 

When i said disabled thats pretty much what i meant about disabling the codes for no ses light. Still no luck?

 

No such luck, even with a 100% stock tune.