MY03, it currently has about 75k on it.
Today morning, it was just fine. After work, I got in my car and turned my car on.
CEL light came on as soon as I turned my car on.

I can't really pin point out anything that might cause CEL to come on.
It was after 9 p.m., so I couldn't even go to local auto store to borrow the OBD reader.

Only thing that I can think of is the major difference in temperature, but I don't think
that would be the reason for the CEL to come on, is it?
Today morning, it was about 50'ish when I was driving to work.
However, in the evening, it was about 35 and I turned my car on while AC was on as well.
Oil seems to be on good level and good condition as well (still clear, no darkness, yet).

What could it be?
I just can't go to sleep so easy knowing that my car has CEL on. ;(

 

nothing you did would cause it. all you can do is scan it.

 

No code = no answer. Probably EVAP.

 

Are you sure it was a CEL and not the Maintenance Required light? Just a thought...

 

Ok. It wasn't a maintenance light.
Next day morning, after about 5 mins of driving, the CEL turned itself off.
I was planning to scan for code after work but it went off by itself and hasn't come back on.

 

It will be a stored code.

 

goto the car store and scan the code. lol.