Msggunny
Member Since: 19 Feb 2013
Location: Holly Ridge, North Carolina
Posts: 4
  
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This is just to chronicle the issue I had with fault P0171. I noticed that there were some others here who had the same issue but couldn't find resolution with a few exceptions.
History: The fault popped up about a month ago. I reset it with my code reader in hopes that it was just an intermittent issue or bad gas (petrol). No joy. It came back a bit later. I did the cursory check for a vacuum leak but didn't have a smoke machine, i used propane in the hopes that it would make the engine rev when the leak was found. Still no joy. A few weeks later i finally broke down and sent her to the dealer. They used a proper smoke machine and found that the EGR valve and PCV valve along with the oil filler tube were all "leaking". After replacing the valves the dealer did a test drive as per spec and re read the fuel trim. All was good with the exception of one value. Although not out of spec and wouldn't throw a CEL and code, it was very close to the threshold. The dealer mentioned that for some reason that when D3's and RRC's are driven for a while in lean fuel mode it seems to throw off the MAF sensor. I agreed to have it replaced as i apparently didn't need the extra $200 i had in my pocket. After the MAF sensor was replaced the codes came back down well into the "good" range.
I love my LR3 (D3) but i need to find a good tool that will allow me to read the computer and make adjustments myself. The labor alone was astronomical (for my tastes anyways), parts was easy.
Hope this might be some assistance to anyone with the same issue.
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 26th Feb 2017 1:39 am |
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Mk1_Oz
Member Since: 21 Feb 2017
Location: Adelaide
Posts: 13
  
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Thanks for the info.
I am no expert but surely the PCV and EGR systems dump into the air inlet system BEFORE the MAF sensor so any leaks in those components would not upset the fuel/air mixture?
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| 26th Feb 2017 7:55 am |
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