Buy OEM 2004 Subaru Part # 44651AC080. Catalytic Converter Heat Shield. Cover Complete Converter Pipe (Right, Front, Upper). Exhaust Manifold Heat Shield A tinny ticking

Cover Complete Exhaust. Heat Shield used on the Catalytic Converter.

COVER COMPLETE-CONVERTER PIPE FR UPR RH Catalytic Converter Heat Shield

Fits Legacy, Outback, Tribeca

Exhaust Manifold Heat Shield
A tinny ticking, buzzing, or rattling noise that sounds like it's coming from under your 2004 Subaru may be a bent or rusted exhaust heat shield.