Flashing 4wd & low range

My 2014 Tacoma (80,000 miles) has been great for the 7 years I’ve owned it. Never a check engine light or any light. My battery died a week ago (original believe it or not). A day after I changed it, Check Engine light comes on as well as the “Trac Off” light. At the same time my 4wd & low range started flashing, while still being in two wheel drive. The fed/low range lights shut off if I turn off the engine and restart. Codes checked, cleared, says it was an air sensor. Was fine for a week. Now fwd low range lights will come on intermittently, usually a few minutes after driving. Check engine light/trac off light came on again today.making me nuts. Only thing different was changing the battery. Thanks for any help or insight into this.

 

I'd start with making sure the battery terminals are clean and tight.
Other than that, I'd need to know the code(s). And have a look at wiring diagrams.