Hi,

I had the engine light come up on me and when I checked the codes, it came back with P1148. Someone told me I have an issue with my O2 sensor / Bank 1.

Is Bank 1 the passenger side?

Would I need to pick up an upstream O2 sensor? Some manufacturers list them as Right hand and left hand. Which side is bank 1?

I am offered Bosch or Denso? Which one is better? Or should I just save $$ and go with the Ebay stuff? Is it all the same?

How hard is it to change on my own? Any writeups? Do I need to use any sealant, etc?

Thank you for all your help!

If it matters, my Xterra is a 2002 Xterra S/C w/ 115k miles on it.

I believe bank 1 is the passenger side/right side, though I could be wrong.

It'll definitely be the one that's further forward. That code means that the vehicle failed to enter closed loop mode due to the front heated oxygen sensor.

I don't really have an opinion on which one to go with - just depends on the cost I guess.

Replacement is really easy. You need to buy an O2 sensor socket. It's just a deep-well socket that has a cut up the side for the wire to hang out of. You just unplug the wire from where it attaches up on top of the motor somewhere, put the socket on the sensor, unscrew it (it might be a bit difficult to undo... these things get hot), screw in the new one, and plug in the cable.

I don't know if it's hard to get to at all on a stock X. My 3" body lift makes getting to everything much easier.

Here is a pic of the sensor in question from when I replaced my cracked exhaust manifolds:


I wouldn't put any kind of sealant on it. If it doesn't want to come right out you might put some PB Blaster or WD-40 on it.

Oh - if you look real close at the pic ( full size link ) you can see that the O2 sensor sits in a little size adapter to make it big enough for the hole in the cat.
I think when I removed mine the size adapter let go first - so after I removed it I had to put it in a vise, unscrew the old O2 sensor from it, and then reuse the size adapter on the new sensor

Awesome thanks for the all the info.
I went to my local autozone today, they told me bank 1, is passenger side and that is considered ast LEFT side. (looking in from hood)

Can you confirm?

Thanks!

The Nissan service manual assumes you're sitting in the driver's seat. driver's side = left. passenger side = right

Awesome. That was really great info. Thanks for all your help! Wish me luck with this, I plan to do this over the next few days.