Buy 2004 Subaru Outback INTER Cooler. Intercooler If your 2004 Subaru Outback is equipped with a Engine, Acceleration - OEM Subaru Part # 21820AA252 (21820AA251)

Intercooler.

INTER COOLER ASSEMBLY Intercooler

Fits STI

Intercooler
If your 2004 Subaru Outback is equipped with a turbo and you've noticed a reduction in acceleration or a hissing on acceleration accompanying your check engine light, your intercooler or its piping/tubes may need to be repaired or replaced.