I have been experiencing while cruising down the road a stumbling or sudden jerking of the motor like it's missing. The engine light came on and code saved was "Misfire" I have taken this into Subaru numerous times and they keep saying they dont know what it is they claim. I'm getting tired of shoveling $$ atr them to no avail. Wondering if anyone else has experienced this and if so, what was outcome. Coils and wires have been checked, spark plugs replaced. Any help would be appreciated.