So I'm getting these 2 codes, and my mileage seems to have gone to hell as well. I had an issue with that whole wiring harness a few months ago. It had came loose and rested against the exhaust and melted just a little bit, then somehow grounded out and blew the fuse, and shot every code related to that harness. All O2 sensors, transmission, etc. So I separated and taped all the wires separate, put new loom on and tied it back away from
The exhaust. All codes went away, and then these 2 came back, and keep coming back after clearing them. Could the sensors have been blown? Or possibly another wiring problem?

 

And incase my sig doesn't show (posting from mobile site) the truck is a 2000 F150, 4x4, 5.4L if that makes any difference

 

There is still wireing issues on the passenger side for front and rear sensors.
Take another look at the harness and repairs.
Clearing codes with a fault present will always come back when the PCM does it's testing and finds them again.
It's not always instant but when the test are scheduled to be done during the drive cycle.

 

Thanks. I just wasn't sure I'd it were possible to actually have killed those sensors or not. I'll have to re-inspect those wires. Wish I knew which color they were odd-hand instead of chasing them Around

 

I don't have the color vs which circuit handy.
The colors are two whites a black and a grey from an OEM sensor.
Unplug one and use a meter to see which pair has 12 volts and note the pin location and colors in the socket that feeds the sensor.
The remaining pair would be the sensor output.
Do not try to measure 'the sensor' output leads with an ohm meter. The meter has a battery in the circuit that may damage the OX sensor part that is not meant to have a voltage applied.
If you have an old sensor, cut the leads off near the body and use it for a test lead access to the harness socket.
If the existing sensor output is faulty, the only two ways you could see it is direct voltage measurement with the motor running or with a scanner set to monitor the outputs of all the sensors as the motor runs.
The front ones will be hunting all the time.
The rears will be slow acting, that is normal unless the cat assembley is faulty.
Use a digital voltmeter for these measurements to see the output swings as it sends corrections back to the PCM.
The motor will run without any sensors plugged up but will run rich and degrade fuel mileage because when the PCM does not get corrections from the sensors it reverts to fixed fuel tables that are rich on purpose to protect the engine from going lean.
Good luck.

 

And the rich mix would also explain a slight lack in power I've noticed. Also starting to notice a tick at certain RPMs that's beginning to scare me