Yes, there are some caveats as there may be a lot of different Y fares with different rules, but ExpertFlyer is a good source for that, although it is a paid service for the most part. If you want me to check it out just give me an idea of which airline it should be and what's the origin/destination, I can do that for you.

EDIT: It seems like Y fares are fairly easy as there is only two of them, and none are very special, here's a screenshot for JFK-LHR