So I was calculating my Rapidash’s EVs and noticed that they go above 252. Do EVs have a new cap or is this an oversight? Or am I missing something?
EVs always go to 255 max, however competitive players only use 252 because every 4 EVs is one stat point, hence the extra three EVs don’t make any difference and should be used towards another stat. Make sense? 
Well the 4 evs=one stat point thing is news to me, but the number of EVs overall for Orobas (my Rapidash) is higher than that. I calculated 269 EVs.
The EV total over all stats is limited at 510, as it is in the original games. Please look up these kind of things before asking a question. http://bulbapedia.bulbagarden.net/wiki/Effort_values
Ok. I understand it now.