I'll take it that you've reset it, but here's the list of things to check,

-air intake hoses (check the ones by the airbox and the IACV valve)
-fuel line pressure/injector blockage (run some fuel injector cleaner through the system, Redline fuel system cleaner (Pep Boys has it) is the best stuff in my opinion in an all-around cleaner
-A/F sensors (doubtful), but sometimes as a result of a crack somewhere on the exhaust itself, either right off the manifold or underneath the engine)
-MAF sensor (needs to be cleaned)
-engine coolant temperature sensor (rare), because other codes P0115, P0116 would be involved
-exhaust system- as mentioned above by a/f sensors