RipPow99XJ

​​​​I've got the P0135 and P0132 codes on my '99 XJ with 250k miles. I purchased both upstream and downstream sensors from partsgeek online. They sent me the downstream and refunded me for the upstream due to stock. I then purchased the upstream on eBay using the parts number 13399 I was given by a tech at auto zone. Both are Bosch sensors. I know NGK/NTK is supposed to be best but I was unable to find them.
The first image above is the upstream and the second is the downstream. Both connectors seem to be correct based on images I took of the connectors beneath my vehicle. However, the new upstream sensor looks identical to the downstream. Both the new one I received and the one currently in my vehicle. The upstream in my vehicle now has multiple holes around the top that remind me of the holes on some rifle muzzles. The one I got... does not. I asked the seller before purchasing if it would fit my vehicle for the upstream sensor and they confirmed. Auto zone confirmed, eBay seller confirmed, part looks off. I know those are not the most reputable sources lol. So that is why I'm posting here before I try and install. Thank you

bluejeep2001

The upstream and downstream sensors are all the same . The different part numbers account for upstream-grey connector and downstream- black connector...and the different wire lengths. The up and down sensors you got are the same sensors, just made by someone else then the ones you have in there now.

RipPow99XJ

Phew! What a relief. Thank you