I have 2 oscars that have been together since they were about an inch long & theyt are now 11 & 12 inches long but now & then they get to fighting,now I know its normal etc but they are at it again but this time its been going on for 3-4 days & the smaller of the 2 has got a few battle wounds (nothing terribly bad) & is hiding in a cave laying on its side to fit & is ther most of the day except for feeding time is there any way to end it. Should I seperate them or let it run its course.

You are correct, a little banter between Oscars is not uncommon, especially if they are breeding pair. However, the aggression between your Oscars does sound like pure aggression and nothing else. The fact that the Oscar is hiding away means that it is frightened. In situations like this, I think it would be only fair to spit them up if it carries on for a long time and injuries up being caused. Oscars that do get on/Pair up will not fight for three days.

People might advise you to put a divider in to separate the fish, in my opinion, this is a complete waste of time because they would just start fighting again once the divider comes out. Maybe give them a little longer and see what happens, they may well settle down, but I wouldn't hold my breath. It's not nice having to get rid of fish for this reason, but you do have to think about the fishes welfare, you cannot have two fish that are constantly fighting, it will only end in heartache.