As posted here:
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The fuel filler does rust out (it just happened to me) and it was the cause of my EVAP failure codeYES,
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was the place to call for the parts. Asked what parts they normally replace and they told me (Arlington Subaru of Massachusetts told me nothing other than the pipe (and boy where they wrong. I'm glad I called Premier & I paid nearly $75 less (and that was with shipping).The one thing I would alert you to is that there is a small valve just at the top of the fuel filler pipe. The valve was not shown in the exploded view in my Haynes manual. And yes, mine was very rotted and I just couldn't see reinstalling only to have to disassemble. Be sure you check the condition of that value before you purchase parts (otherwise you'll be in the middle of the job without all the parts to complete the project)
Also, the screws at the top of my tank seemed quite hard to remove - I'm not of the metal they were made from but I broke 3 impact phillip heads drivers trying to remove them and my drill didn't seem to dent them but I finally worked them out.