Is there supposed to be that metal flap/door thing? I can't remember. I got a "Check Fuel Cap" on my dash so I went to tighten it. Then I noticed no flap thingy. I couldla swore there was one, but I can't recall.

 

Never mind, found the answer in another forum. Cobalts don't have 'em. Car won't start and I'm looking at everything, never noticed it was never there!