2012 6.7 107k miles, EGR deleted, turbo back 5" straight.

Been having an 02 sensor circuit high issue for a few months, even though I'm deleted it.

So found plugs full of corrosion due to not buying the plug kit.

Cut off plugs from the harness and sealed them up, but it didn't cure light.

Assuming maybe one of the other disconnected plugs to the exhaust system may have corrosion too.

Also, intermittently last 2 months, I had the lightning bolt and "brake torquing brake voltage while acceleration," warning that I cured that with a new brake switch.

But now, lately, my suspicions are increasing as my left rear turn signal is warning me, but then there are times warning goes away during the turn cycle "ok, it's a cheap Amazon led maybe resistor is going bad."

Last night my dome light was dim unless I smacked the light, and that is random so far as I know, but this morning I had no AM/FM sound, not even static, then just randomly came on.

I'm at my wit here.

I tested battery voltage and load test independently when I tried the O2 plug repair.

I applied battery cleaner and the purple guard on the post.

I have seen some green in my cables but not excessive.

I'm going to clean my ground straps and mounts next, I guess, as this is driving me insane. ANY OTHER SUGGESTIONS?

Oh, and very rarely, I get a service 4wd warning, but it goes away when shut off and start back up.