After doing research and verifying what you said I also came to conclusion that the oxygen sensor should be changed first witch I ordered original. I had my whole exhaust replaced and these two front sensors are denso so I just soaked them in some fuel additive to try to clean the tips. Not sure if this ruined them but I wanted to try this because I was getting a o2 code and eventually it went away. At the time I didnt wanna replace them because of the price and the code was not coming up. Now I am getting same codes you got. I am going to replace the one in the front but do I need to replace the 2nd one or can I wait to see if the check engine light stays off after and just drive it. They are both denso but not sure how old they are and I did take them out and soaked the tips with the holes in a gass additive over night to see it that helped. I definately think I need to change the fron one because of the code but starting to think i should change the 2nd one to cause I soaked it in additive and may have messed with it or should I just drive it after changing the one?
