Stalling/dying

[Chylla]

I need help. I have a 1995 Subaru legacy wagon 5 spd.She has been stalling and dying constantly. This is what I have done so far: changed spark plugs and wires. Changed fuel filter. Changed core.Changed throttle position sensor.Cleaned throttle housing.retrieve codes(throttle pos.sensor. misfire in engine 1 and 3) She has all the symptoms of a bad Erg valve. Stalling loss of power bad fuel mileage. But erg is not where it should be. Even had a shop look we are stumped as it say my car has one. What I haven't done:fuel injectors. Oxygen sensor. Erg.) Car is costing me a lot of money. Can anyone help please? Thank you Chylla