When I first took possession of my car, I had to replace the entire filler neck. My car had never had the recall neck installed and the large filler tube on a USA car anyway, is mainly a fairly thin, molded rubber item and was badly cracked. The gas cap is originally a female cap and changes to a, more normal for the U.S., male cap with the recall item. I don't remember that T fitting on a U.S. car, BTW. That seems to be an area that warrants an inspection every so often, especially if you have the old style female gas cap, the rubber filler is likely "toast" by now (but my car was probably the only one left like that)
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Charles