Vacuum leak, injector or injector circuit problem, possible low compression come to mind. May need a mechanic to smoke test for vacuum leak, perform an injector balance test and run a compression test on #2 cylinder, that is the center cylinder on the passenger side, if you want to try some testing.
Do you feel a misfire at any time when idling or driving? A look at the freeze frame data (global mode $02) will show the conditions under which the code was set. That information helps to narrow the focus with the testing.