Just opened up and looked at the diagnostic report the OP posted.
P042800 is shown as a pending code. This was before the battery was changed.
The pending is significant by way of saying the sensor is working but has picked up a reading that is out of range but not a major issue yet.
The next obvious question is if you scan the car now has it changed to permanent ? If its flagging as pending then see if it will clear and go from there. It could be a loose connection causing an intermitent fault. If its permanent then some more fault finding is required and reading the live data to see what the voltage is doing at part 25 on the diagram when driving.
The fault code you have is esentially telling you there is an intermittent fault between sensor 25 upstream of the cat and the sensor post cat.
Unfortunately this is where you can end up throwing the parts bin at the problem without live data from the diagnostics.
The engine managment system is comparing readings between pre and post cat sensors and saying the reading from the pre cat (25) is not consistant with what it expects. Although its talking about temperature the PCM is monitoring the voltage which should fluctuate rapidly on the live data at the pre cat sensor. If the live data shows it is stuck at say 0.75v then it should throw a permanent error. If the voltage fluctuates and then randomly sticks at say 0.55v then returns to normal you will get a pending error as per the uploaded diagnostic report.
Now as to possible causes :
Check the wiring on both the pre and post cat sensors and the connectors for damage / corrosion.
Check for any possible air leaks at the pre cat sensor part 25.
Check the cat is not clogged. If you can read the percentage from the autel if its high either take it for a long drive at higher revs to force a regen or use the dignostic tool to force a regen. Your other options are using a cat cleaner or a physical exam of the cat with a boroscope to see how clogged it is.
It is possible the catalyst is on its way out which would throw the same code your seeing if the cat is getting too hot because it is clogged. Hence the suggestion to use a cat cleaner to improve its performance.
The sensor post cat could also be sending incorrect data to the PCM suggesting that the CAT is operating too hot based on the compared figures at the PCM from pre and post cat sensors.
The last option i can think of is either a fault on the PCM module or the wiring to the PCM in which case your going to need to probe the sensors and check the actual voltage signals against the one recieved at the PCM.
Link below which will explain more eloquently than i have.
@philw696 can you think of anything i have missed ?
