1647 code
 

Hello all. New subscriber here. Wife was gifted a 1999 xk8 with 60k miles last year from her mother. What a wonderful car to drive. Reason for my post is check engine light came on. Borrowed a scanner from a coworker and pulled up a P1647 code. AutoCodes says a malfunction bank 2 upstream. I understand this as the passenger side sensor before the cat. I located a sensor in front of the firewall near the back of the engine. I understand Denso is OEM for O2 sensors and ordered an upstream sensor Denso 234-4720. When I disconnected the electric connector from the car, the existing sensor on the vehicle has the identical connector as the one on the new sensor I purchased. These will not connect to each other, obviously. I double checked my purchase and am convinced I have the correct replacement sensor. Now I am thinking I have located the incorrect (downstream?) sensor in the car. I have searched and cannot find the proper location of the upstream sensor on bank 2.
Any help would be appreciated, I am not sure what now to do?
Sorry for the long post, but if you are not too bored by now, FIGGIE is the name my mother-in-law gave the car. Said he was “figment” of her imagination when her husband bought it for her.

Figgie, Jon89 did his over the winter and I think a god writeup.
I'll call him and see if he can come in to add to the problems.
I do know they are all on the fire wall right together and are gray and black connectors that have a funny way of coming out of the clip.

I had to replace the Bank 1 Upstream oxygen sensor in my wife's 2006 XK8 in late December 2020. This car has the 4.2 engine while you have the 4.0 engine, so there may be some differences in configuration and layout. My OBDII code was P1646 and my new replacement sensor was a Denso 2349029 (purchased from amazon.com for $86). I have monster hands and while I could get to the failed oxygen sensor to remove it, my hands were much too large to get to the electrical plug on the other end of its pigtail. My small-handed neighbor came over to help me with this job. We removed the air intake tube assembly and he used a small pair of needlenose pliers to wiggle the correct electrical connector somewhat loose from its metal bracket attached to the firewall. Once he created enough room to get two fingers underneath the electrical connector assembly, he was able to pop it up and out of its bracket. I remember that the four oxygen sensors' electrical connectors were all lined up in a row in that bracket. The black connectors (rear oxygen sensors) were first, and the grey connectors (front oxygen sensors) were next. The trick was to tug back and forth on the pigtail while watching the bracket to ensure that we removed the correct connector for the oxygen sensor we needed to replace. Once the connector was loose from the bracket, remove the locking plastic pin and squeeze the connector in its indented spots. It will eventually release....

No idea how much any of this information will help you but I wanted to provide all of my notes regarding the job to you....

The AJ-26 engine in 97-98 and AJ-27 (VVT engines) from 99-02 use different sensors. To avoid using them in the wrong application, Jaguar used the same connectors; but, with the opposite male/female pin configuration.

The fundamental difference is the AJ-26 only uses a heater in the upstream (3-Wire) with just 2 wires to the downstream. AJ-27 has heaters (3-Wires) for both.

Most parts suppliers don't make the application distinction, which results in your situation.

Thanks for your post. The car is definitely a 99, built 07/99 with last numbers of vin 42117. Maybe a model change as you have suggested. In my original post I stated that the replacement I purchased had the identical connector as the car, both male which wont connect. Upon closer look, the connectors are very similar but slightly different with original having two “keys” if you will and the replacement with only one. By keys, I mean slots that have to match to be able to slide together. I found a Denso site which pulled up two options for upstream O2 sensor. One a number 234-4720 which is what I purchased. The other was number 192400-6080 which is the connector I need. That number will not pull up in any parts sites I have checked. About ready to put her back together and take it to dealer for service. Wife had a Land Rover Discovery when we met, and I was so glad the day it died. Something about these British cars?

Initial reply was incorrect and meant for another post. The Denso site is use ful to locate their suggested replacement for 02 sensor and some others also