P0171 on my ZX2 | Ford Escort Owners Association (FEOA)
  1. Wash your hands and do not touch your face, keep it safe and clean. Long live Feoa!

P0171 on my ZX2

Discussion in 'ZX2 1998-2004 2.0L DOHC' started by some, Oct 20, 2020.

  1. some

    some FEOA Donator

    Messages:
    14
    Likes Received:
    0
    Trophy Points:
    61
    Hey guys, today I got CEL - P0171 - I inspected everything, the PCV and everything around the intake is quiet - also the hose that is known to go bad has already been taken care of with a rubber hose and a plastic plug, I will have to post a photo of what it has there. I dont have bad idle or anything, I am figuring that I am looking a dirty / bad MAF or even just need to replace the air filter?

    I am going to start there.

    Thanks for any insight!
  2. Apex

    Apex FEOA Member

    Messages:
    37
    Likes Received:
    3
    Trophy Points:
    8
    Location:
    Colorado
    The best way to diagnose lean or rich codes is with fuel trim data. You'll need to look at your long term and short term fuel trims over a range of RPM. If your total trims improve when you rev up the car then you are most likely looking at a vacuum leak somewhere that you missed. Are you able to look at live data and see what the fuel trims look like? You'll save yourself a lot of headache if you diagnose the problem before you start replacing parts.
    some likes this.
  3. some

    some FEOA Donator

    Messages:
    14
    Likes Received:
    0
    Trophy Points:
    61
    use elm327 bluetooth for live data?
  4. Apex

    Apex FEOA Member

    Messages:
    37
    Likes Received:
    3
    Trophy Points:
    8
    Location:
    Colorado
    Yes, that should work fine if the app you are using has live data it should be able to read fuel trims.
  5. some

    some FEOA Donator

    Messages:
    14
    Likes Received:
    0
    Trophy Points:
    61
    I replaced the dirty air filter and cleaned the MAF to start, but I am going to take it in if the drive cycle doesnt clear the code in the morning, and see what the shop has to say. I ordered an ELM but I really need to get it to pass emissions. It already was within readiness as well - I should have taken it sooner then later :rolleyes:
  6. Apex

    Apex FEOA Member

    Messages:
    37
    Likes Received:
    3
    Trophy Points:
    8
    Location:
    Colorado
    Definitely ok to do that, since the filter needed to be replaced and cleaning the MAF is basically free, but I wouldn't start replacing parts that you don't know are bad. I would suggest learning how to use your scanner while you're waiting to receive it, you might even catch something the shop doesn't.
  7. some

    some FEOA Donator

    Messages:
    14
    Likes Received:
    0
    Trophy Points:
    61
    I replaced the air filter and cleaned MAF, code has not re appeared! If getting P0171 ONLY, and no vacuum leaks or surging, dirty MAF and air filter for sure, at least with my car. Here is how the intake manifold is setup also
    [​IMG]

Share This Page