Yet another O2 Sensor question.

[gardengirl38]

I went back and read everything I could find on O2 sensors under this forum.

I got a check engine light and the code read P0133 Ckt O2 Sensor slow to respond Bank 1 Sensor 1.

SO I thought I would replace it since its 21.99, here is where I run into a snag. At Auto Zone there are four sensors and they do not call them 1,2 1,2 or left, right etc... The description says rear upstream sensor rear downstream sensor and front upstream sensor front downstream sensor. SO when I look into my jeep from the drivers side of the engine I can see two sensors that are side by side, and further down which I believe is after the catalytic converter I can spot one, I havnt searched hard for the other yet... but when I look at the first two up top is that upstream and how do I know which one is which as far as which would be the front upstream and which would be the rear upstream... what the heck... this is frustrating. I need a diagram. I have tried to order a Haynes manual for my Jeep with no luck yet. Anyway I want to learn this stuff but have searched the web and just hear conflicting information. Some posts say I dont have four sensors, some say I do... Some say if my Jeep was made for California I have 4 but if not I have 2... I want to know what the heck to replace haha. Seriously, I have almost 100k on the jeep and thats the recommended check/replace schedule on the sensors. And should I rent the tool for doing this? Thanks for any thoughts...

 

[xt master]

I know on my 97 with a 2.5l engine I have 2 O2 sensors.

One after the manifold connects to the down pipe and one between the cat and muffler.

 

[EarthCruzn]

I had the same problem......... change both sensors, the back one was my un coded deal.......... it was more money though.

 

[gardengirl38]

I definitely have four, I have two catalytic converters one sensor on each of those then two other sensors after the converters on the pipes going out...

I just dont know which of the two before the converters is which... and when I look up the parts they dont seem to have the same part numbers for what they are calling them so it doesnt seem like they are the same... I have no problem changing both of the front or even all four but Id like to understand why one of them is sensor 1 and which that is... ugh... lol

 

[JPNinPA]

You need the upstream front O2. Each one is a different part # and don't mix them up.

Here is how the equate:

Bank 1 Sensor 1 is upstream from the front cat and is located on the front ( towards the radiator) manifold just before the flange.

Bank 2 Sensor 1 is upstream from the back cat and is located on the rear ( towards the firewall) mifold just above the flange.

Bank 1 sensor 2 is downstream from the cat located just below the mini cat off the rear manifold.

Bank 2 sensor 2 is downstream of the cat located just below the mini cat off the rear mainfold.
Hope this makes sense.

Check is you have an exhaust leak near there. I did and it would throw the P0133 until I fixed the issue. I still plan to change the O2.

 

[gardengirl38]

THANK you very much!! I found a good tech manual online too and a picture of the engine with the banks numbered Thanks this is helpful !!
Just an update, I changed out the sensor today and it took a total of about 5 minutes. That was the easiest thing I have ever done on the Jeep~! I feel empowered !! Thanks again for your help. This is the best place for advice and info

 

[JPNinPA]

Mind sharing the link to the manual??

 

[gardengirl38]

Download PDF Jeep Wrangler 2004 Service Manual | PDFTown.com Not an exact match for the one I own... but I think its better than nothing, its pretty informative.