How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Greg Your Own Question

Greg
Greg, Technician
Category: Lexus
Satisfied Customers: 6810
Experience:  Import tech
29331485
Type Your Lexus Question Here...
Greg is online now

What does it mean when the diagnosis says " P0171 system too

Customer Question

What does it mean when the diagnosis says " P0171 system too lean (bank 1 )
Submitted: 1 year ago.
Category: Lexus
Expert:  Shantal-Mod replied 1 year ago.
Hello,
I'm Shantal and I'm a moderator for this topic.
I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.
I was checking to see if you had already found your answer or if you still need assistance from one of the Professionals.
Please let me know if you wish to continue waiting or if you would like for us to close your question?
Thank you,
Shantal
Expert:  Shantal-Mod replied 1 year ago.
Hello,
I apologize as we have not yet been able to find a Professional to assist you. Do
you wish for me to continue to search for someone to assist you or would you
like for us to close your question at this time?
Thank you for your patience,
Shantal
Expert:  Greg replied 1 year ago.
Name is***** goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back,

Hi P0171 could be quite a few things that would trip this code.

The engine air/fuel mixture is too lean,

There is too much air or too little fuel.

Common causes:

  1. Intake or vacuum leaks
  2. Clogged or faulty Mass Air Flow sensor (MAF)
  3. Faulty PCV valve
  4. Stuck open purge valve/solenoid
  5. Failed or faulty oxygen sensor (bank 1, sensor 1)
  6. Improperly installed aftermarket cold intake
  7. Low fuel pressure
  8. Clogged catalytic converter
Sometimes this code can be caused by a bad MAF sensor ,might be a good idea to check this and clean it with MAF spray cleaner .

Then clear codes and test drive if the check engine light stays off then all is good if it comes back on check for codes ,still a P0171 then check the other possible causes .

Please get back to me with the reply button, and not the poor or bad service, this way i can get back to you or suggest another expert if needed.

Your deposit does not pay me until the answer is rated in a positive way,
Not rating or a bad rating does not constitute a refund, if you are not happy or you have sorted out your problem before the answer then please let me know.

Kind regards Greg.

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Greg

    Greg

    Technician

    Satisfied Customers:

    1080
    Automotive diagnostic tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Technician

    Satisfied Customers:

    1080
    Automotive diagnostic tech
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    4443
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Diagnostic and repair technician

    Satisfied Customers:

    453
    Licensed diagnostic and repair technician
  • http://ww2.justanswer.com/uploads/RO/RobMechanic/068.64x64.JPG Rob's Avatar

    Rob

    ASE Certified Technician

    Satisfied Customers:

    82
    30 years trade experience
  • http://ww2.justanswer.com/uploads/UK/ukiaibal/2012-11-9_205920_SAM0109.64x64.JPG uk_iaibal's Avatar

    uk_iaibal

    UK Car Mechanic

    Satisfied Customers:

    1
    Verified Car Mechanic.
  • http://ww2.justanswer.com/uploads/NA/nabilc/nabilc_avatar.64x64.jpg Billy's Avatar

    Billy

    Trainer/ Master Technician

    Satisfied Customers:

    38
    Trainer 8+ years, master tech. 10+ years, SAE member