This is a replacement factory up pipe for the 2006-2014 WRX and 2004-2021 STI
When Subaru switched to the 2.5L motors from the 2.0L EJ20, they switched to this up-pipe as well, so 2002-2005 WRX cars can gain a performance advantage as well, but you will need to source a 2.2K ohm resistor in place of the factory EGT sensor as the new pipe will not have provision for the EGT sensor. This applies to early 2005-2006 Legacy GT/Outback XT as well.
Fits the following Subaru models: