Join Date: Mar 2007
Location: Dutchess County, NY USA
Car: '14 Subi OBW, '02 Subi OBW (gone now, but well loved), '15 Toyota Sienna, '13 Honda CR-V
My 2014 shop manual lists P0300 as a valid code (Random/Multiple cylinder Misfire Detected), but it's always possible that Subaru's software writers suppress it in favor of an outright cylinder designation (P0301 thru P0304). Consistent with what you mentioned, my 2002 manual does not include P0300! Either way, the OP's recovery of a P0302 code points him in a direction to start looking.
He'd get even more info if he can capture the full freezeframe data. Then he can see if other cylinders are getting into the act (a systemic issue) or if it's isolated to the one.
2002 OBW base model with automatic. Added: CD player, Security System, tweeters & subwoofer, trailer hitch, lighting mods, cabin filters, hood deflector, drivers lumbar mods, winter tires.
2014 OBW Premium, CVT & Moonroof. Added: trailer hitch, lighting mods, upgraded horn, winter tire/wheel/TPMS package.