O2 CEL after first DE day - on the way home

[brewerbry]

I ran my first DE track day yesterday - what a blast to really see what these cars can do! Car ran well during the event (other than cooking the old brake fluid - lesson learned, change the brake fluid before the next DE!)

While driving the 2 hours home, after about 90 minutes of highway driving, I hit stop and go traffic and got a CEL light.

I checked the fault codes this morning and they were all O2 sensor issues. I reset them and the codes have not come back (yet).

Any ideas of what would cause the CEL in the first place?

Thx-

[Ben006]

02 sensors can go bad.
or, your cats.
what were the codes ?