Without seeing scanner data or knowing what mods it might have is hard to pinpoint the exact cause but the car has 95,000 miles on it and O2s SHOULD be replaced every 30,000 miles

So it can be o2s are just too old, they got corrupted from cheap gas, wiring for them have got burned, exhaust leaks, not installed ( like the rears) or even the fuse for O2 heaters is blown

If the fuel was too rich or lean then the PCM would be tripping DTC error codes for that and not O2 DTCs which are pointing to O2 failures.

Yes it would cause loop issues as PCM seeing all 4 O2s with problems.

You have to get under car and look to see if all 4 are installed, is there any wires fried, is there any exhaust leak from flange at heads all the way back to rear O2s.

If CATs are installed they could be clogged up, taken out, or leaking.

Fuel pressure, either dirty gas filter or worse would cause engine to run like crap and most likely trigger lots of engine knock.
Simple check as to test valve at end of fuel rail allows a pressure gage plugged in and then rail pressure should be 58 PSI.

Of course past owner when selling car took some mods off and the tune they have in it now is crap to engine makeup now.