[David2012F10]

Hey guys second post on here thanks for all the help on the last one. I have a 118102 Mixture control 2 rich, a 12AB04 oxygen sensor after cat signal open circuit and a 12B701 oxygen sensor heater after cat function: internal resistance too high. Would these be fixed by just changing out the O2 sensor? (my car is completely stock and from what I read people with catless have some of these issues)
I also got 930769 Deactivation of terminal 15; upper startability limit reached, 93076A which is the same thing but deactivation preventer active and 9308B0 which I suspect is just the car asking for a new battery.
Any input/guidance/words of wisdom is appreciated. Thanks.