O2 sensors, loss of mileage, control arms, and burning oil

[foxhallfred]

I have had a check engine light issue for some time now. the codes indicated O2 sensor. I have ordered them. I am wondering their location, and advice for installation. Also, I have a creaking noise right front passenger side. I am told it is the control arm bushing. Is this described as an upper control arm when ordering a new part? I have lost 80-100 miles per tank of gas, is this because the O2 sensor finally failed completely. I am a half a** mechanic at best, will I be able to to the O2 sensors and control arm myself? The car seems to burn a little oil too. any tips here? Thanks alot for all your help

Josh

[Towncivilian]

I replaced a rear O2 sensor in my Pathfinder in 2 hours or so, when it was dark and it was my first time replacing one. You'll probably need a 22mm or 7/8" oxygen sensor socket for proper removal and reinstallation of the sensor. Here are the locations of the O2 sensors:





If it's the front O2 sensor, that is very easy and you should be able to R&R it in 30 minutes or less. That would also explain the extreme loss of mileage.

I don't know about the control arm, sorry.

For the oil burning issue, change the PCV valve if it's easily accessible. Its location is shown in the first diagram above.