Trying to figure out AFR reading

They should match. If they don’t, believe the plug. But verify that too because you can be lean on the plug and dead rich in the chamber.

That doesn’t look lean from what I can see. You really need an otoscope to look into the shell of the plug where it meets the porcelain. There should be an .080-.100 wide fuel ring around the bottom of the porcelain.

What plug is that and what fuel. It looks a touch on the hot side.

Edit: why are you going through sensors?? One thing that will kill them is using silicone that isn’t O2 safe.

If it doesn’t say specifically it’s O2 safe it may not be O2 safe silicone.