A 1996 XJ is OBD1, so it should only have 2.

 

That's the ones I am questioning

 

So which do I need for better mpg?

 

Those are the ones i'm questioning too. I think that two of them are universal, i.e. have to splice the wiring, one is an alternate and the other four are the ones that we need that plug right in. "Which one is for fuel economy"?? I'm not sure, however the two upstream ones are what the computer will adjust air/fuel ratio against, i think. If i were you, i'd crawl under that jeep and count the number of sensors that are actually on it just to make sure. In terms of "are these actually what we need"? Hopefully someone will chime in here...

 

OK, so i cross referenced the part numbers i got from Amazon, Bosch parts numbers 13138, 15465, 13122, 13100 with the part finders on autozone and advanced auto websites. I got matches every time. So, for the downstream rear manifold use #13138, downstream front manifold use # 15465, upstream rear manifold use # 13122 and for the upstream front manifold use 13100. They were all listed for use with california emissions. If anyone has conflicting information, please post it up!

 

For those of us with the pre-cats (Cali emissions) these are the same part numbers I was able to find using Mitchell on-demand. So I would say those are the right ones!!

And just in case there is any question.....

Upstream = ones before the cat
Downstream = ones after the cat

 

That's great news, thanks for checking there too. I really love the fact that jeep decided to use 2 different exhaust and engine management systems on the 2000 year model. Makes life really easy...

 

I bought two of the Bosch 13100 for the upper's. I hope they work...

 

Thanks I bought two of the 13100 using your info. I hope these are what I needed for the uppers

 

OK, little update on the O2 sensors. Bought all four Bosch as discussed above. They all went in OK, and what i mean by OK i mean a total PITA. The upper ones are a disaster cause you have no room to work and can't see them. The lower rear was the easiest. The lower front was a whole different ballgame. Not only is there no room to work but the sensor is planted right against the oil pan. The Bosch replacement is fatter and longer than the factory one. I had to get out the BFH and "clearance" the oil pan to get it to fit. Other than that, all the connectors were spot on and hooked right up and the lead length was right. So, if you are going to buy the Bosch ones, get ready to give the old oil pan a little beating....I best be getting some better gas mileage now...We'll find out tommorow...If anyone has bought all four of them and done this but had a different experience, lets hear it.

 

just get the numbers off your jeep?

 

So I bought two 13100 from amazon. They gave me one 13100 and a 13425 or something. It was for a new model Mercedes V8. Wtf!?!
So instead of returning it to Amazon
I tried swapping it out at 3 different parts stores. The first two said no cause I didn't have a receipt. And the third said yes. Come to find out that it was a $209.99 part. They gave me the right one and $153 cash back! All I did was want to trade it for a new one...cha-ching

 

^^^ honesty, apparently no longer the best policy?

 

buy 13100 and 13138 from AAP, use these codes to get them for cheaper, and just pick up in store.
Receive an Extra 20% off Sitewide w/No minimum w/Coupon P20.
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I believe the 13100 were both upstream, and the 13138's were both downstream.

my 2001 has a split manifold, and i can say that even with a 4.5" and it up on jackstands it was a little rough to monkey my arm up there.

if you lay with the pumpkin right over your neck and follow the exhaust back up you can feel the oxygen sensors, i personally followed the wires out (they are both viewable and pretty easily reachable from drivers side of the engine bay) and cut them, slid a 7/8" box wrench on there and popped them off, after the initial pop they are finger loose.

attach the new wire, drop the sensor down, and attach it and finish tighten with the 7/8's open side. be patient with these, they are expensive and feel like they can break with a bit too much push.

cleared all my O2 related CEL codes.

total time start to finish (with never have doing this before).. probably an hour and a half.

 

It used to be until I realized that giant corporations are the real crooks. Plus I said I wanted to exchange them and didn't care about the difference