No that means whatever you are using to scan the car doesn't support testing the upstream sensors. I would suggest you get someone involved who is more experienced at this point. The car has a mechanical issue that wasn't there before you worked on it. You need to find what you did, even if it was accidental, that is causing the surge now. it won't be the O2 sensors.

 

It's just a crude OBD tool which doesn't understand wideband (aka linear) O2s. There are plenty of other tools/software that do.

 

Not the news I was hoping for, but I'm sure your right
I guess I'm actually lucky because this will be the first time in 15 yrs of maintaining the car my self (with the help of this board) that I now have to find
a good professional repair shop to take over.

I'm still grasping at straws here but, Is there any chance that the new O2's I bought are a bad Chinese knock off ?
I positive I couldn't have damaged anything while replacing the O2 sensors, its very straight forward plug and play.
Changing the coils and plugs is also a P&P , all though the wiring harness for the coils was a little brittle I was very
careful of that as well.
But if I did tweek a wire wouldn't it show up on the scan tool as a bad coil ?

 

These are the parts I used, the ratings were good and the Denso parts cost to much


O2 sensors > Coils & plugs >

 

You should at least invest in a code reader that can read the Jaguar specific codes (or DTCs, as they are called).

Best regards,

Thomas

 

Mine does , I recently got one that's approved by this board.
It has been reading all the Jag codes so far,

 

My apologies, I got the impression that you had a more basic code reader.

Best regards,

Thomas

 

That's why its more confusing for me, the scan tool read everything in the DTC
it just seems to have a problem with the 2 up stream sensors

 

Some can also grasp what these other wideband O2s are, don't give up.

They cost more but give instant far better readings so the car can control fuel etc better.

The parts you fitted may be OK, you just need a tool to help you get data. Even an elm327 with suitable cheap software can do it.

 

@CKMJAG you do not really know that the problem is with new O2 sensors. You just assumed it, because racing begun after you changed 4x O2 sensors. Re-reading the post I would do following:
plan to spend whole day on this:
1. TAKE CHILL PILL
2. you have at least one good upstream O2 and 2 good downstream sensors the ones you pulled from the car. I know there is a procedure how to remove coaxing from O2 sensor elements, I never used it myself nor have direct experience with it. Just so you know.
3. Lookup on the net how to diagnose O2 sensor with multimeter. Again, I know there are instructions on the net, I do not have first hand experience with those.
4. let's go back to original setup less one bad sensor.
Does engine still race?
swap remaining good O2 sensor
Did this change anything? Just playing odds that you have two bad sensors are less than getting one bad sensor.
5. Begin replacing remaining sensors one at the time.
This plan ASSUMES that you can return to initial state. If you did, then your work has not changed anything else.
Still, what I describing can go sideways at any point and this will require to adjust the plan!
Best of luck!
One other advice, it was mentioned already before: STFT and LTFT you have to display them in a graph mode. run engine at idle and see if STFT on both sides changing beyond 10% when engine racing; do same while holding throttle steady so engine runs at 2500rpm.
If you can corelate spikes in STFT you either have a vacuum leak or malfunctioning MAF sensor. I may be off a little about 10%.

 

JagV8,
Can I ask a big favor of you ?
I looked on Amazon for a elm327 , there are dozens of them !
I very happy to spend the money to get one and learn how to use it.
I just don't know which one to pick , could you please take look at the
Amazon page and identify which one I should get ?

Thank You !!

 

Big Koska,
Great ideas, I saved and labeled the oem one that came out ,they can go back in their original spot.
I will use your test procedure and see what happens.
I don't understand what the STFT and LTFT is all about, I will try the other tests first then try to wrap brain around STFT and LTFT
I appreciate all the ideas and input you guys are offering , Thank you ..

 

On places like Amazon it's a guess plus I'm in England

 

I replaced the B2 S1 sensor with the old but good sensor from the other bank, I left the remain 3 new ones in place.
It idled better and drove better but still has the surge but as bad.
It looks to me that my new Chinese O2's sure are suspect.
I took some more scan readings, see attached, as I cant really know how to interpret them

Today's readings >

 

Part 2 of the scans can load here I've exceeded my MB limit
I realize the few scan pictures aren't enough info for a diagnosis of the problem but given
that the motor reacted favorable to the Good/used B2 S1 sensor now in place of the Chinese new one, would this not
indicate the problem is just bad cheep brand O2s .
I guess the next test should be to replace both S2 sensors with the original ones which were working.
If the motor responded even more favorable but still had a "tiny"surge because it still has one Chinese S1 sensor in it.
This might further point to replacing all 4 again but this time with DENSO units.

Do you think I should go this route or stop and look into the ELM327 tool ?

 

Hey something doesn't jive, when I had 4 Denso sensors the scan tool was able to do a scan and tell me that there is a P1647 code, which is a
bad O2 sensor at B2S1
Now with Chinese sensors the scan tool play's dumb and says (the vehicle does not support) How can this be .

 

I've removed and returned the cheap O2s & ordered a set of Denso's, I had to eliminate the O2's as a possible cause.
If it fixes it fine if not I can move on and dig deeper.

 

It's FIXED ! the new Denso O2 sensors did the trick. It runs really smooth now !
I really want to thank the guys on this board for the time they spent trying to help me figure out what was wrong.
If this helpful knowledge base wasn't here I'd have to sell our 04 XJ8
Thanks, again ..