labpedro

Okies, so I got the P0031 Ho2s error a while ago, and wanted to sort it out so bought a sensor from ebay a while ago which was supposed to be the right one (which it wasnt) so got another one off a chap on here. fitted it this morning and still the same. Ive reset the ecu (2003 wrx) with my obd2 reader but the damned thing just wont go away. i suppose my question is, would the rear o2 sensor throw the same error or is that a totally different code altogether.

any ideas chaps and chappesses?