This is an OEM Subaru 2.5L oil pan, required to fit a aftermarket headers on a 2002-2005 WRX. The 2.5L oil pan allows for clearance of the crossover pipe on the Perrin header. This is the stock oil pan on all 04-20 STi and 06-14 WRX models.
Subaru released the newest oil pan (111009AA151) to replace the (11109AA131). They are structurally the same but the 151 has an internal baffle and does not spray oil everywhere like a shower head when the drain plug is removed.
Warranty Disclaimer: Subaru of America will only warranty parts installed on a car that has a matching VIN to that part.
Warranty Disclaimer: Subaru of America will only warranty parts installed by a CERTIFIED Subaru Dealership. The part being installed must also match the vehicle VIN. IE If you install an STi block in a WRX at your friends shop, do not expect a warranty claim to come through if it explodes! Please use your best judgement.