I just purchased a set of upper oxygen sensors for a 99XK8 and was told they would also work with a 99-03 XJR. The part numbers are different, but I know this doesn't always mean they aren't the same part. They look the same, but wondered if someone could tell me for sure.
Thank you , Louis

 

I have one I took off my 2003 XJ8 if you want me to measure it or take photos.

 

Yes....they should work.
The 'upstream' O2's are heated and should have the long grey plug with four pins.
The wires should be two black, one blue, one white.

 

Thanks xjay8. I probably should be more certain next time, but I got what I would call a good deal on them, so took a chance.

 

Here are some photos I took this morning -- sorry for the poor quality!

I took this sensor off my 2003 XJ8.

 

Old Mike, thanks, and that does match what I have.

 

Well, first, I dont know where the statement that there was no redesign of oxygen sensors for the AJ27 engine came from!. That is wrong. The AJ 27 engine uses wideband lambda sensors for the pre-cat position. A simple browse through the JTIS data or the epc will show that. The AJ 26 does not.
The second factual problem is that there cannot be a sensor that is compatible with the MY 99 through MY 02 XJR, since the MY 99 XJR has an AJ26 engine and later is an AJ27.

Now, with all of that said, the MY 99 XK8 hs an AJ27 engine and the MY 00 XJR also has an AJ27 engine, so you should be fine with the sensors.

 

Wish I could find where I got that info -- sorry if I was misleading or downright wrong. Incorrect information can be the worst thing to post -- I'm feeling bad now!

Hopefully it won't be an issue, again I'm sorry for posting what appears to be bad info.

I just went back to my other post and took out the info about the engine upgrade, etc.

 

It is a common mistake in online parts suppliers to show the AJ26 / AJ27 engine change for the XJR as being 1998 / 1999. (the year XJ8s changed) For that reason, I always look at the recommended parts for MY 98 when I buy for my MY 99.

The attached pdf shows the MY 99 update information. Note changes to lambdas starting on page 21.

What I don't know, but I THINK, is that the connectors for the upper lambda sensors for the AQJ26 and AJ 27 engines are different. Can anyone confirm this?

 

G'day Ross....yes, I can confirm that the plugs for the two engine types are different.
The earlier AJ26 engine up to Sept. '99 has the longer grey plug.
The AJ27 engine post Sept.'99 has the shorter grey plug and they are not interchangeable

 

I guess that's why there are not so many misapplications! The Jag engineers did do something right!

 

Ross...you will also find a large variance in prices for the sensors, especially the earlier long plug Denso's ;o))
Ask me how I know ;o))

 

Hello Xjay8 & Sparkenzap - thanks for the info (or more like confirmation of what I found out a few days back....)

Sparkenzap was helping me with advice on my post "jag xj8 failing emissions on tickover"

I'd got to the DTC P1647 and had pulled out a spare HO2 from a 1998 xjsport, hoping to swap it into my main xjsport... only to find the connectors were male and female....

Like you say, Jag engineers got that one right.... my poor xjsport is still running in FuelSys OL mode and I still have a P1647.

But! with 2 new upstream lambda sensors waiting at home, this evening will be fun putting them in their rightful place and we'll see what the result is...

thanks again /steve