Trying to resolve a P0171 CEL
 

Been running through the list of problems that can cause a P0171 with intermittent Restricted Performance, not getting P0174. Idle Long Term Fuel trims are B1=8.6%, B2=6.3% at 2,500rpm B1=13%, B2=11%. Changed plugs, Upstream O2 sensors, replaced leaking brake booster O-ring that was loose and leaking. Smoked engine and replaced EGR valve and thinned and split EGR tube from a used 2005 S-Type R. It looked like there was a vacuum leak between the EGR valve and the manifold. Found one of the EGR bolts was loose. Smoked engine again and not seeing a leak at the same point but looks like there is a leak around the EGR valve area.

Is it possible for an EGR valve to leak smoke? The Brake Boost O-ring is sealed now. Is there anything else around the EGR valve that can leak smoke, very hard to pinpoint but seem to be getting a reasonable amount of smoke.

Maybe try spraying soapy water during the smoke test. With any luck, it will look like Lawrence Welk turned on the bubble machine and you can further isolate the source.

I am having similar hard to track down issues with those codes as well. A smoke test revealed leakage at the throttle body shaft and the EGR valve. When I researched the cost, I determined that I'd be living with the current parts :) Most expensive EGR valve I've ever come across. And, some research indicated the EGR valves and throttle body shaft do tend to leak anyway. Is that the cause of the codes? Given that mine throw under acceleration and not idle (as in the case of a vacuum leak), I am not sure it is in my case.

I've replaced both upstream O2 sensors and now get much more consistent graphs from them, but I still have high long term fuel trims (~15) I can't seem to reduce. The lean codes fire when the LTFT numbers are too high and so the quest continues. The original MAF was intermittently failing and I've replaced it a couple times (a Walker unit was way off and resulted in a horrible idle; the replacement Delphi unit is consistent but I'm not sure it is absolutely correct for the car's airflow). The MAF and O2 sensors have helped a lot in reducing the occurrence of "restricted mode" but I still feel the fuel trim numbers should be better. I just wish I knew what "normal" was :)

If you have not tried this already you may well find that the Jaguar SDD software (V130) will give you a more acurate identification of a faulty component or at least what sensor is giving the signal that is causing the fault. (But it may not!)

Again if you have not already got it and if it is any help here is a link to the Jaguar workshop manual:

http://www.jagrepair.com/images/Auto...M-Workshop.pdf

Mellow

Would you happen to have a link for the 2000 shop manual for a 4.0L? Thanks in advance.

JTIS, in the Stickies.

I have that, but it doesn't work on our computers. We use Windows 10 and it is too old for that. A manual like the 2002.5 would be perfect.

Well I run windows 10 too but have it working.
Windows 10 has a number of backward compatibility tools you can use when you install things.
Here are the instructions it's already built into windows 10. Allows compatibility all the way back to Win 95!

Run Old Programs

It's pretty easy so give it a try. JTIS is the best we have and it's not that good either!
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try this...i run win7.....https://drive.google.com/drive/folde...3Z?usp=sharing

Not so, as has been posted.