The "check engine" light is on. I did the 'key-dance' to see if I could get the p-code but I didn't get any. But there is the oil symbol on top of the odometer.

This happen to me 2 weeks ago but wait 3 hours and light turned off. And I texted my personal mechanic and told me it could be a faulty sensor or gas cap.

Also, I was in LA last night when the light came on. Drove 1 hour home and car had no issues. Drove this morning around the block and freeway, went 70. Still no issues.
Mess around and examine with the gas cap. No cracks or damage on the cap. And engine light is still on.

My mechanic is off today, so can't get ahold of him.

Should I be concern?

2005 limited
68k
Bought used at 67k
Dealer replaced all sensor, rotors, and break pads.