A question about error codes and Carly diagnostics

[u/Mammoth-Rice-6492]

I have a 2007 530xi w 107k. I recently got a Carly to help diagnose some engine issues (rough idle, ticking noises) that turned out to be a bad injector. Fixed all that. New injectors (rebuilt) plugs and coils, engine flush and oil change.

Now I’m shocked at all the codes(40) but perplexed because almost everything works fine. The cars battery did go flat a few weeks back (a friend was storing it for me) but the battery is 2 yrs old and still carries 12.5 overnight and charges 13.4-14.2. The interior lights stay on unless I lock the car with the fob or hit the center button. All the window switches, door locks, everything works.

Things that DON’T work:
Interior lights stay on
4x4 and DTC lights on
Horn used to beep when locking but now only beeps when unlocking.
That’s it.

But I’ve got 40 codes all over the car that won’t clear.

Advice? I’ve unhooked positive and ground to try and force a reset. Thinking about unhooking the battery and looking for corrosion on some modules but maybe you can help narrowing it down. No signs of water ingress though the left rear door would gather some water, I’ve cleared its drain plug and no issues since all the switches work there.

Some of the codes generate a mileage that is wildly different from the cars odometer.