TJ Wrangler 2004 Manual
 

Does anyone know part numbers for both Oxygen Sensors before and after Cat? 2004 TJ Jeep Wrangler Manual

Would be help as getting multiple numbers on different sites.

J

It’s always safer to read the part number directly from the sensor as there are so many different p/no’s for O2 sensors depending on the emission standard the vehicle is built too, there is Calif, Federal and Euro standards in every given year.

I've just purchased two sensors from RockAuto - haven't removed the old ones as yet so I've taken a bit of a punt but from my research so far, a 2004 may have 2 or 4 sensors. The 4 sensor versions have two pre-cats at the manifold so you have upstream sensors before each. My 2004 auto only has one cat, just in front of the muffler and there is an O2 sensor between them. The other sensor is further forward, roughly in line with the firewall. I spoke with a Jeep dealer and they told me that my VIN was only showing a single sensor - part number 56041887AA - the upstream sensor. I also ordered the downstream one - 5139021AA. Haven't been able to fit them as yet so not sure if they will fix all the error codes I'm getting.

In my experience with WG is that the emissions package was described as euro spec. Neither Californian nor Federal.

Oxygen Sensors
 

Yes, my upstream is 56041887AA, just cant see number of the downstream version. Could you keep me informed of your downstream number when you do work.

Finally managed to get it to the mechanic, the new sensors cleared the codes but not for too long, a few days later they were back. One of my problems is the PCM was replaced some years ago with a rebuilt unit from the US and it keeps showing errors for sensors and pumps that aren't fitted. I've got it booked in with a Jeep dealer to try and get it re-flashed with the correct software and hoping that will fix it.