DTC P015A O2 Sensor Delayed Response - Rich To Lean (Bank 1 Sensor 1)
WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For the diagnostic procedure, refer to DTC P014C. < Refer to
DTC P014C O2 SENSOR SLOW RESPONSE - RICH TO LEAN (BANK 1 SENSOR 1) , Diagnostic Procedure with Diagnostic Trouble Code (DTC). >