I am getting P0171 & P0174 faults about every 800 miles: System too lean bank 1 &2. I have changed MAF sensor and done an inductive fuel line flush at the dealer. Do you think I might need to change spark plugs which have over 150k miles on them? If so Can you give any pointers on how to get to the back 3?
Thank you,
Mark Clark QEI

 

They need changing.

Save yourself hassles and read existing posts on here about those codes (top of page, at least use Search, try the codes, try leak, hose elbow, things like those). You should never keep clearing codes without fixes. In this case you may have damaged the cats, sadly.

 

I'm with John, your plugs need to be changed, but I doubt that solves your problem. Definitely have a look on the vacuum elbow, as well as the entire vacuum plumbing...but the odds say it will be the elbow.

But...er..."back 3?" your V-6 is surely not transverse-mounted?!? Shouldn't that be an even digit? (back 2, 4?) I've changed 'em on our 03 - somewhat different arrangement from your model, though I think they are nearly identical once you have the upper and lower intake manifolds off. It's been a year or two...but I don't recall a problem getting to any plug.

 

Thank you,
I meant left- underneath on the 3 plugs (V6) that appears to need a new gasket if I pull apart to get to that side; I am looking for this elbow .

 

Check this thread out Mark:

https://www.jaguarforums.com/forum/s...ics-faq-52720/

 

Mark, unfortunately for you....Rick has a post MY 03 car. Otherwise, you'd have great pictures and how-to's!

The elbow is on your 2000 - I b'lieve at the rear of the left side. Yes, there are uppper and lower intake gaskets and you must be diligent in ordering to get the proper part. Now...there ARE pics somewhere here of the vacuum elbow I'm talking about - have seen 'em - just can't remember exactly where....don't fear it....I think you have to remove at least the upper intake to get at the elbow...then may's well attack the lower and change your plugs. There are how-to's with pics on here somewhere..look in the sticky's.

btw...I had those two codes on the 05 and it actually WAS the MAF, but you broke the rules by changing that first...you're s'posed to search hi & Lo for at least 3 days' time for vacuum leaks first!

 

Ahhh my good man. But within the linked thread, right there in the very first paragraph goes abit deeper than the 2003 and up!


"In an effort to aid in the infamous P0171 and P0174 codes that lead to a lean running condition, I have color coded all vacuum lines.

I believe that the following pictures will go from MY (Model Year) 2003 on up. There seems to be some confusion with 1 vacuum elbow located under the lower intake manifold. I believe this elbow is on MY 2002 and older, this is a known failure. Heres a link to replace them: http://jagrepair.com/VacuumLeakSType2000.htm <--THANK YOU GUS!! There is also a rubber elbow located at the back of the upper intake as well taht is a common failure as well for the MYs 1999~2002"

yep, right there in the blue hyper link! Right before "THANK YOU GUS!!

 

Busted!!! Now you know I never read...only look at the pretty pitchahs!!!

 

I just had a 3.0 last week with that exact issue. Lean codes, and a squealing noise you could actually hear inside the car! Collapsed and perforated elbow under the intake at the rear of the engine, per usual. Not a bad job if you are up to it!