Fault codes P0171 and P0174 - Jaguar Forums - Jaguar Enthusiasts Forum

Notices
XK / XKR ( X150 ) 2006 - 2014

Fault codes P0171 and P0174

 
  #1  
Old 01-30-2019, 08:32 PM
Junior Member
Thread Starter
Join Date: Mar 2018
Location: Shrewsbury
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Default Fault codes P0171 and P0174

Fault codes P0171 and P0174.


Hello all, has anyone had any experience of these codes? They are for ‘system running lean’ on each bank. The engine check light repeatedly comes back on once cleared in my 100,000 mile 2006 XK 4.2. Looking back at the history, I can see these codes have been showing up for several years. A leak check on the intake system was carried using a smoke machine 4 years ago with no leaks found, the mass flow meter was replaced which apparently cured the issue.

A year later the codes showed up again, fuel pressure sensor was replaced along with pipework.

The codes are back again… I have had the car for a few months and it sounds and feels healthy. MPG is only 16 or so, but I do quite a lot of short trips.

I am going to get the car serviced soon, some online research suggested it might be something as simple as a blocked air filter causing this, but I am keen to know if anyone here can offer any insight?

Thanks in advance everyone.
 

Last edited by paulguitar; 01-30-2019 at 08:41 PM.
  #2  
Old 01-30-2019, 09:39 PM
Stuart S's Avatar
Veteran Member
Join Date: Aug 2010
Location: Atlanta suburbs
Posts: 4,944
Thanked 2,056 Times in 1,334 Posts
Default

Those codes are likely to be caused by a vacuum leak. Your XK is 13 years old and the rubber hoses dry out and crack over time. See this old thread, beginning with Post #6: https://www.jaguarforums.com/forum/x...arging-178162/
 

Last edited by Stuart S; 01-30-2019 at 09:41 PM.
  #3  
Old 01-31-2019, 03:18 AM
Veteran Member
Join Date: May 2009
Location: Yorkshire, England
Posts: 22,920
Thanked 3,345 Times in 2,967 Posts
Default

In case it's not that, you can check if it's an air leak somewhere else:
get an OBD tool with live data e.g. elm327
get engine hot
park
watch LTFTs (see my sig) at idle
rev to about 2500 and watch them again

If they drop a lot it's an air leak (perished hose or whatever). If not, post the numbers and see if anyone has ideas.

Running so long with the codes may mean one or both cats are in poor shape, sadly.
 
  #4  
Old 02-02-2019, 08:22 AM
IanXF's Avatar
Senior Member
Join Date: Apr 2012
Location: FL
Posts: 175
Thanked 39 Times in 28 Posts
Default

Check plastic vacuum lines in front by throttle body follow to radiator I had several cracks in those lines causing the codes
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ian20x
X-Type ( X400 )
3
12-16-2017 08:20 AM
noterman
XK8 / XKR ( X100 )
7
08-18-2016 09:11 PM
mjlaris
XK8 / XKR ( X100 )
14
07-07-2014 04:32 PM
timxtype02
X-Type ( X400 )
3
03-12-2008 07:17 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: Fault codes P0171 and P0174


Advertising
Featured Sponsors
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: