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2007 Prius Code P0171

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by llg, Jul 27, 2017.

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  1. llg

    llg Junior Member

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    I need some additional help please. I just purchased a 2007 Prius w/ 140,000 miles and right after buying it from an individual I got on the highway to head home and the check engine light turned on...a real bummer. As I drove it home, I noticed that when I got up to about 60+ mph I could hear a sound (the best description I can give is high pitched but sounds like air...not sure if that makes any sense). So, I took it to get the code/s and it's a "P0171 Bank 1 system too lean" w/ no other codes showing up. After researching some ideas on this forum, I cleaned the MAF (twice) and checked the throttle body (which after looking at the car records was cleaned recently). I'm trying to decide if I should replace the MAF or if there might be some other things to throw a P0171. One other detail is that the previous owner had the oil changed that morning before I purchased the car. Any help/advice would be greatly appreciated.
     
    #1 llg, Jul 27, 2017
  2. valde3

    valde3 Senior Member

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    Only the check engine light? No other warning lights? What did you use to read the codes?

    If there are no other codes and no freeze frame is information available you just have to check live data. Comparing fuel trims, MAF, front air fuel ratio sensor, and rear oxygen sensor should tell you what is wrong with it.
     
    #2 valde3, Jul 27, 2017
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  3. bisco

    bisco cookie crumbler

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    did you check the oil level?
     
    #3 bisco, Jul 27, 2017
  4. llg

    llg Junior Member

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    Thanks for the response. The oil level is good.
     
    #4 llg, Jul 27, 2017
  5. llg

    llg Junior Member

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    Thanks so much for the reply. Only the check engine light and no other warning lights. I actually went to two auto parts stores and they used their machine. What do you mean by freeze frame? What would I use to check live data...or is it something I would need an experience Prius mechanic to do? Thanks again for helping me troubleshoot!
     
    #5 llg, Jul 27, 2017
  6. fotomoto

    fotomoto Senior Member

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    Those generic readers can't always see hybrid specific codes.
     
    #6 fotomoto, Jul 27, 2017
  7. dave3057

    dave3057 Member

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    Lean code I believe. Could be a couple things. Air leak behind mass air flow sensor would be something to look for. Air fuel sensor could be bad. Fuel pressure issue. Kinda just throwing ideas out there lol
     
    #7 dave3057, Jul 27, 2017
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  8. llg

    llg Junior Member

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    where would you suggest I get codes (aside from dealership)? I am in a small town with very few good (hybrid) mechanics? THANKS!
     
    #8 llg, Jul 27, 2017
  9. llg

    llg Junior Member

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    Thanks so much for the suggestions. Guessing to find those issues I might need to locate a good hybrid mechanic...might be out of my skillset!
     
    #9 llg, Jul 27, 2017
  10. m.wynn

    m.wynn Senior Member

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    No, just a good mechanic. A lean code is a combustion engine issue, not hybrid drive related. A good diagnostics guy shouldn't have much trouble.
     
    #10 m.wynn, Jul 27, 2017
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  11. Raytheeagle

    Raytheeagle Senior Member

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    I have been getting the P0171 on our 2010 Prius II with 159 k miles on it.

    I have a basic scanner (Kiwi2) that I have paired with Dash Command app for my iPhone.

    It tells me the code so I can research it, then determine a course of action.

    So far this have only cleaned the MAF sensor, but that cleared the code for awhile. But it has since returned in the most recent days:(.

    I'll try cleaning the MAF again and see if that helps.

    As has mentioned above, my next go dos are the O2 sensors, but we'll see if the code reappears when I am due for a smog check in December ;). I have not noticed any driveability issues to date when the code appears or when I reset it.

    Hope that helps(y).
     
    #11 Raytheeagle, Jul 27, 2017
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  12. m.wynn

    m.wynn Senior Member

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    Gen 3 P0171? Shotgun a fuel pump into that pup, parts changer style. No diagnostics whatsoever...:D
     
    #12 m.wynn, Jul 27, 2017
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  13. JC91006

    JC91006 Senior Member

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    Time to buy another maf sensor
     
    #13 JC91006, Jul 27, 2017
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  14. Raytheeagle

    Raytheeagle Senior Member

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    Thanks for the suggestion (y).

    The P0171 seems to set more in the summer when the ambient temps are higher. Might be something to that;).

    My old man has a 99 Jeep Cherokee that had a fuel delivery issue (the fuel rail is DIRECTLY above the exhaust manifold so there is vapor lock on startup). Ended up wrapping the rail in insulation and that has helped a lot :). But the fuel pump is on its way out though:(.

    Can you monitor fuel pressure on Techstream?
     
    #14 Raytheeagle, Jul 27, 2017
  15. llg

    llg Junior Member

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    Thanks, will see about getting someone else to run the codes for me.
     
    #15 llg, Jul 27, 2017
  16. llg

    llg Junior Member

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    Good luck fixing your vehicle. Thanks for sharing your experience.
     
    #16 llg, Jul 27, 2017
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  17. Raytheeagle

    Raytheeagle Senior Member

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    Agreed. That's a good course of action.

    They can be had for ~$75 on Rock auto, so we'll see if it passes smog prior to buying and replacing. But if it sets and won't clear, that's a good go do.
     
    #17 Raytheeagle, Jul 27, 2017
  18. Raytheeagle

    Raytheeagle Senior Member

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    Where in the great state of NC are you near? If you tell us the general location, we might be able to help with locating a mechanic .
     
    #18 Raytheeagle, Jul 27, 2017
  19. llg

    llg Junior Member

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    Brevard
     
    #19 llg, Jul 27, 2017
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  20. Raytheeagle

    Raytheeagle Senior Member

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    Just south of Asheville. Beautiful part of the country:).

    You opposed to going to Charlotte for servicing?
     
    #20 Raytheeagle, Jul 27, 2017
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