Rep Power: 187

So 2 days ago when I started my car the area where the mileage pops up said "Check Fuel Cap".
I did so, and its screwed on fine and everything.
The message has continued to pop up every time I start the car since.
This happened once before, but turning the car off and then back on fixed it and I didn't see it again until now, now it comes on every time I start it.

It's more of a nuisance than anything, but is there anything I can check to get it to go away, maybe a simple fix or perhaps a fuse is out or something?

I have a 2006 LX Sedan.

(It might fix itself again, if it does I'll let you guys know)

 
Rep Power: 308

Pretty common on 8th gens when temps change.

Can you press your reset button on the left side and clear it ?? (may not on earlier models)

 
Rep Power: 187

Yes, pressing the button on the left, the one that switches between the trip odometers and the oil life, will make it go away, but it is still popping up every time i star the car.

 
Rep Power: 518

From memory:
The system must run and pass its "evaporative emissions" monitor self tests 2 or 3 times in a row before it will turn the message off by itself.

This does not happen immediately and it does not happen on demand, and it could take some time before the car is in the correct conditions to even begin a self test, let alone complete one. It can take a few days for most average drivers, depending on conditions.
This is explained a little better in your owners manual.

Once it has been able to do this, the message will go away.
If it repeatedly fails its self test, then the message goes away and is replaced by the Check Engine Light.



You could go to a parts store that does free check engine lights and get them to erase the CEL memory.