Stopped at Autozone, had them pull up the code - P0455

That helped me come up with a better search here. Lots of threads and the answers I need. I had already decided to try a new gas cap. No luck there - none at any local Chrysler dealers (or none anywhere near where I need to go in the next few days), and it doesn't seem anyone makes an aftermarket one. Looks like I'll have to order one.

What about Mercedes dealers? Would they have the same gas cap, or is it a Chrysler only thing?