Could be a number of things...
You can try to reset the ecu as Fredoops said. Or maybe certain parts are clogged and need to be cleaned out?
Have you tried the upper engine cleaner, they're about 25-30 dollars from Subaru.

Quote Originally Posted by bbell View Post
is there a simple way to do this, otherwise im going to need to take it somewhere
There's a few DIY ECU resets in the DIY forums, have a look there~