Silly Question about Gas Cap

So for the last few months, I've had my check engine light on my 111,000 mile 2005 Prius going off sporadically. Everyone tells me it's the gas cap, but I've been putting off replacing it because I want to make sure I get something compatible.

Do I need to go buy a special gas cap of any kind, or will one of the 10 dollar Slant replacements off of Amazon work?

Also from what I've read, I should expect it will take a few drives over 20 minuets before the check engine light clear outs, assuming it really is just the gas cap, right? When Should I start to expect something else may be wrong?

Thanks!

 

Thanks for the reply! I hope its that easy but I took the car into my Mechanic on friday, got an oil change then. Still have the check engine light on. (He didn't replace out the gas cap for me though.)

He's a big fan of if it isn't broke, don't fix it, point of view. I often have to fight with him to do repairs rather than wait until something really breaks, which is one of the reason i like going to him. He's never recommended getting un-needed repairs.

 

Hmm, the maintenance light isn't on anymore, just the check engine light. Not sure if those instructions are meant for the maintenance light or the check engine light. Also I shouldn't do this until after I have replaced the gas cap right?

 

Ok, that Stant fuel cap was the one I was looking at, just purchased it. Thanks!