2001 xj NKG 02 sensors

[Xjin85]

Hey guys,

So my 2001 xj has been idling a bit rough and shakes going more than 40MPH. The check engine light is on so I ran some codes and I came up with:

P0158
Bank 2, Sensor 2
Oxygen Sensor
SHORTENED TO VOLTAGE.

So I am planning on changing both sensors in Bank 2:

-Sensor 2 (downstream sensor) and Sensor 1 (upstream Sensor)for good measure.

So I have a few questions before I get started.


1) Are the sensors I need to order #23110 (pre-cat) and #23099 (post-cat) for bank 2?

I need DIRECT FIT O2 sensors for 2001 XJ... federal Omissions (not CA compliant). From my research here on the forums, it seems NGK 02 sensors seem to be the best. But I a confused about which part numbers I should buy to replace both sensors for bank 2.

I found these that I think will fit Bank 2 sensor 2 with a direct fit. Will these work?

https://www.amazon.com/gp/product/B001PNCKJA/ref=ox_sc_act_title_6?smid=ATVPDKIKX0DER&psc=1

I can't seem to find an NGK DIRECT FIT 02 sensor for Bank 2 sensor 1 that matches. Can anyone give me a link?


2) I also came up with code:

P0456
Evaporative Emissions Leak
Monitor Small Leak DETECTED

This makes sense as my exhaust system is rusted and is barely hanging on. I am in need of a full replacement probably. I was thinking of just buying a new car all together (https://www.amazon.com/gp/product/B001NZYMGO/ref=ox_sc_act_title_1?smid=AB9Z3SET61WJF&psc=1 ) snd just install the o2 sensors directly into the new cat before install. I like the thought of having a dual exaust.

What do you guys think?

 

[Xjin85]

https://www.cherokeeforum.com/f2/code-p0158-204645/#&gid=1&pid=1

 

[Ralph77]

I am little confused.
While not a 100% sure, but pretty sure, I always thought that all '01's were CA Emissions.
In the US that is.
Also you use the word precat which is confusing me more.
So assuming you do have the dual front cat just under the 2 piece exhaust manifold then these are what I believe you need.
What I purhcased for my '00 CA Emissions XJ.

23151 is Upstream; Cylinders 1,2,3; Bank 1 Sensor 1; Calif. Emissions

23110 is Downstream; Cylinders 1,2,3; Bank 1 Sensor 2; Calif. Emissions

23506 is Upstream Cylinders 4,5,6 Bank 2 Sensor 1

23099 is Downstream Cylinders 4,5,6 Bank 2 Sensor 2.

I am also almost positive that a Federal Emissions '00 would use two of those same sensors.
But the Bank 2 ones.
One at the end of the downpiple before it connects to the cat in front of the muffler and the other one at the end of the cat just before the muffler.
In a CA Emissions the upstreams are in the 2 piece exhaust manifold and the downstreams are just below the cats on the front dual cat.

As far as the P0456 I had one once and a new gas cap solved that problem.

 

[75SV1]

My 2000 Federal emissions XJ uses one upstream and one down stream.

 

[THE2NDXJ]

Just as an update in case anyone else comes back to this topic: The NGK/NTK (Niterra) parts locator website shows the updated part number as 23179, and from the way the Fitment Notes are worded, 23179 is applicable to all four positions, B1S1, B1S2, B2S1 and B2S2. I also checked the Napa and Autozone website and for NGK, 23179 is the only part number listed. Not sure why the Bosch and Denso selections are showing many different numbers. From my understanding, NGK was the original equipment company for the O2 sensors. Have fun!

 

[XJ-PRO]

Just as an update in case anyone else comes back to this topic: The NGK/NTK (Niterra) parts locator website shows the updated part number as 23179, and from the way the Fitment Notes are worded, 23179 is applicable to all four positions, B1S1, B1S2, B2S1 and B2S2. I also checked the Napa and Autozone website and for NGK, 23179 is the only part number listed. Not sure why the Bosch and Denso selections are showing many different numbers. From my understanding, NGK was the original equipment company for the O2 sensors. Have fun!

We are on the same boat! I'm currently looking to replace all four oxygen sensors on my 01 (Cali emissions) and been searching all around. I want to stick with renown brands and NTK is one of my options. For all four OEM sensor references which are 56041213AF, 56041212AE, 56041213AG and 56044215AA when inserted into Rockauto's results for all four numbers is only 23179 (NTK reference).
Can it be possible that all four sensors (just the metal part and not wire length related) are the same and have the same measuring capabilities and OEM and some aftermarket references have different part numbers due to wire length related to each individual sensor for its position on the two catalytic converters?

Thanks in advance!

 

[75SV1]

Years past there was an option for a splice in O2 sensor. It covered both front and rear. The rear has a different plug than the front. If you look at the DENSOs, they have different wire lengths. Also, note the plugs on them. One of them one of the slots is a different angle. The NTK does not list its length. One of the slots is very wide.

Edit, I might have used the NTK in my 2000 Fed XJ. I had a new Denso and an NTK. For some reason I had to install the NTK in the rear O2. I installed the Denso in the front (upstream). It didn't run right. Ran better with the old O2. I bought another NTK O2. I think from NAPA. It ran better. It has long wires. I had to fold them up and zip tie them. I'll see if I can check them this weekend. Putting the LS 5.3 back in the Avalanche. Thats been a project in itself.