2004 Subaru Forester XT
Hey guys I just picked up my 04 Forester a few weeks ago as my first car and I love the car so much already but I recently just had my Check Engine Light pop up. Ran the code and got " P0420 - Catalyst System Efficiency Below Threshold Bank 1". I did some research and I'm pretty positive one of my o2 sensors is bad but I'm not sure which one. I've seen a lot of people saying the rear is the one that makes the CEL come on but then why would it say Bank 1 and not Bank 2? Anyways any help would be appreciated and if anyone knows exactly which one is which can you please let me know the location too because i'll be replacing it myself.