O2 sensors, how many and where?

[saar]

Hi,

I want to replace my O2 sensors.
It's a 2001 XJ, 4.0L, 4x4, AW4.

I know about 2 O2 sensors, in RockAuto.com there are 4 different kinds of sensors:
upstream front
downstream front
upstream rear
downstream rear

Their support claims I need all 4 of those, but I don't see where...
Does anyone know what sensor should I buy? (and how many :bang: )
Thank you,
Saar.

[bigjim350]

You have two sensors on the exhaust manifold and two behind the cats. The should be labled as bank 1 sensor 1, bank 2 sensor 1, bank 1 sensor 2, and bank 2 sensor 2. Bank 1 is the towards the front, bank 2 is towards the rear on the exhaust manifold, and sensor 1 is the one on the exhaust manifold, sensor 2 is behind the cat.

http://i11.photobucket.com/albums/a172/Jake4x/buildpics2010.jpg

[saar]

Hi,

Thank you. that is the first time I see that kind of manifold :-)
I have only one CAT which explains why I see only 2 O2 sensors.
I guess my XJ is like the 2000 ones.

Thank you,
Saar.

[bluedragon436]

Yeah yours is probably like an early 2001.. so possibly still a 2000.. since I know in 2001 is when they went into the stupid four O2 sensor setup.. I am tracing issues with my wife's 04 Ram that has the 4 O2 sensors.. and all I can find out from the code reader is a bad O2 sensor.. yeah, not replacing all four at $100+ each..

[BRUNER247]

Imo if your replacing sensors buy mopar or your asking for trouble! Jeeps are very sensitive when it comes to sensors & many times if its not mopar it won't work. I tryd 3 different O2 sensors before I finally bought mopar n solved the problem. & I assumed the part store part was good n moved on to the cam sensor, checked everything several times, tryd another O2 sensor & another week of checking crank, cam, & triple checking everything. I ended up buying a couple sensors I didn't even need, arguing with multiple part stores about their junk, & spending weeks scratching my head. I learned the hard way. Never assume a new part is a good part & always buy mopar sensors.

[saar]

Hi,

I bought Bosch sensors, I hope they will be fine...
I'll update if they won't.
Saar.

[Mudderoy]

Imo if your replacing sensors buy mopar or your asking for trouble! Jeeps are very sensitive when it comes to sensors & many times if its not mopar it won't work. I tryd 3 different O2 sensors before I finally bought mopar n solved the problem. & I assumed the part store part was good n moved on to the cam sensor, checked everything several times, tryd another O2 sensor & another week of checking crank, cam, & triple checking everything. I ended up buying a couple sensors I didn't even need, arguing with multiple part stores about their junk, & spending weeks scratching my head. I learned the hard way. Never assume a new part is a good part & always buy mopar sensors.

I've got a HAM buddy that has been handling Harris county vehicle fleet for years. He told me the same thing, get OEM parts. I figured he was just used to deep pockets and didn't. I've already replaced my new Bosch O2 sensor with a Mopar, and I'll be changing the other as well, replacing the new one.

I bought an IAC from RockAuto Airtex(?) and it failed, yup Mopar will be the NEW replacement, as the old MOPAR is back in there now.

[Mudderoy]

Hi,

I bought Bosch sensors, I hope they will be fine...
I'll update if they won't.
Saar.

They do work, I have 3. One died, one I replaced with a Mopar, the other is still in there, but I'll be replacing it with Mopar soon. My 98 only has two O2 sensors. Upstream and downstream.

[Carves]

apparently ... NGK/NTK is what gets put in the mopar O2 Sensor packet,


Would be good to know what actual brands chrysler sourced as suppliers for all the XJs sensors .....