Check Engine light on/off

[mybenje]

on my 04 4 Runner V8 SE, with 80K, the check engine light keeps going on/off, it was on a couple days ago, after driving for a little bit, turning the car off, the next morning light was gone. I am sure it will come back after a couple days.
I did read that it is most likely the O2 sensor, can someone confirm, it will save me some diagnostics money, and I can go straight to fixing,

Thanks,

 

[SubSonic]

I'd check your gas cap first, to make sure it's tight. Every time I've ever had an 02 sensor failure in any of my Toyotas, the CEL came on and never went back off (until I changed the faulty sensor and cleared the CEL with my OBD scan tool).

Yes, a loose gas cap will pop a CEL in most all modern vehicles. This is why I bought a scan tool (a decent one can cost as little as $100 or less). Saves a lot of time and money by eliminating unneccessary trips to the dealership. Certainly for me and my '00 Tundra, which eats an 02 sensor about every 18 months. The part is about $112 at the local dealer (I make him honor his online price) and the dealersip always wanted about $300 to change it out before I wised up and bought my code scanner.

 

[Nuke]

Stop by a local Autozone and have them pull the code and then go from there. It's free. If you keep getting intermittent CEL's, the codes are probably stacked up.