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PO171-178 codes??

Old May 14, 2019 | 10:25 AM
  #11  
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Awesome! This is waaaay cheaper than the OEM genuine rover one lol. just to be sure, https://www.ebay.com/i/283171982958?chn=ps this is the one i had eyed. Looks good?
 
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Old May 14, 2019 | 12:59 PM
  #12  
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To be honest, at that price its probably a fake. But I will also admit that is about what I paid on eBay and have been using it for over a year. I do suspect that it may be going already because as of late I am getting occasional lean codes. But I still have to do live sensor readings on the laptop to see how things look. (already have new O2 and spark plugs). Premature failure is generally what happens with the fake ones.

For $20 I say give it a go. I may even pick up another myself.
 
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Old May 22, 2019 | 12:30 PM
  #13  
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UPDATE: went ahead an bought a genuine Denso MAF for my LR3 cleared the codes and the po171 po174, po172 po175 codes showed up. MAF isnt the issue. Have any other idea?
 
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Old May 22, 2019 | 12:52 PM
  #14  
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Have you cleaned the throttle body? Have you ever removed it? Since sealing the TB and EGR I have not had any lean codes come back now. Those metal gaskets are one-time use I am pretty sure. Although I used a new TB gasket, I still used a very light coat of Reinzol to seal it.

With that said, I am still baffled about the rich to lean codes. My only other thought would be O2 sensors but they usually dont fail in pairs like that. Other options may be the throttle pedal position sensor or the throttle position sensor itself.

At this point, some live data of the MAF and O2s may help. Not sure if you can view sensor inputs from the pedal.
 
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Old May 22, 2019 | 05:49 PM
  #15  
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ill have to check the TB gasket, i cleaned it and replaced it with a genuine gasket, but with no sealant. EGR i havent fiddled with, so i dont think that could be it, going to smoke test here soon to find if its a vacuum leak for sure. If not, id say is 02 sensors or postion sensor like you said.
 
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Old May 22, 2019 | 06:59 PM
  #16  
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Well sealant is not needed, at least when everything is smooth and new. But several others have sealed things up and it helped clear lean codes. But you are also getting rich codes, thats the odd thing. Of course you could have multiple issues.
 
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Old May 23, 2019 | 08:34 AM
  #17  
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If you have too rich and too lean codes on the same bank, it’s a MAF.

A smoke test will confirm if you have an actual leak causing a lean code.

In addition to changing the MAF resetting adaptions can work. After doing that I would go to a fuel rail cleaning.
 
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Old May 25, 2019 | 02:54 PM
  #18  
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well, if that's the case, the genuine Denso MAF isnt doing its job then. Id reckon i have to buy a genuine LR MAF to get this to work, having a smoke test done Monday to see if its a vacuum leak, if not its either MAF or a fuel system issue. Plus im getting rich and lean on BOTH banks. Not just one, if thats the case it has to be 02 sensors i believe, which 02 are the best that arent genuine LR's?
 
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Old May 25, 2019 | 02:57 PM
  #19  
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I really doubt its the MAF because that would be two completely different MAFs failed in the same manner? If there were the case I would leak towards a harness issue or ECU issue. On the previous page, with the graphic I posted, check the bright green plastic for any cracks. If there is a crack after the MAF you essentially have a vacuum leak/unmetered air entering.
 
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Old May 26, 2019 | 05:08 PM
  #20  
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As a matter of fact, i do have a crack right after the MAF, where the first "red clamp" is shown on the diagram.I have wrapped it in electrical tape hoping it would do the trick, but to no avail, it didnt work. Didnt know it mattered even if the leak was downstream from the MAF. Guess a new resonator is on the list.
 
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