Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    VWVortex


    Results 1 to 9 of 9

    Thread: Code P0171 Caused by Disintegrating Cat Converter?

    1. 04-02-2011 02:32 PM #1
      My '99 New Beetle's catalytic converter is disintegrating after 79,000 miles. The "guts" of the converter are rattling badly at certain engine speeds (I have verified that the rattle is not loose exhaust shields), and the exhaust coming out of the tailpipe smells bad. Not like rotten eggs, but like raw exhaust. This has been going on for a number of months but the exhaust smell has only shown up in the past week or so.

      Two days ago, the CEL came on. I assumed this probably had something to do with unconverted exhaust reaching the oxygen sensor downstream of the cat, but the code is P0171 - System Too Lean. This does not seem to fit with the cat self-destructing, unless maybe the guts have shifted so that the downstream O2 sensor is somehow blocked from sniffing the exhaust?

      I'm trying to determine if I've actually got two problems, or only one!

      Thanks from a newbie / lurker...

    2. Semi-n00b
      Join Date
      Mar 27th, 2011
      Location
      Baltimore, MD
      Posts
      15
      Vehicles
      2001 VW Jetta
      04-02-2011 05:19 PM #2
      My jetta threw the p0171 code and after spending weeks trying to figure out the cause it turned out to be a failing MAF sensor was letting too much air into the engine. You might want to check that. HTH

    3. Member ps2375's Avatar
      Join Date
      Aug 13th, 2003
      Location
      Meridian, ID
      Posts
      11,364
      Vehicles
      80 Rabbit(DEAD), 94 Golf
      04-02-2011 06:31 PM #3
      The second O2 sensor has nothing to do with that code.
      Tradition is the art of making the same mistake repeatedly, on purpose.

      FS:MkI low back front seat upholstery(new)

    4. n00b
      Join Date
      Mar 31st, 2011
      Posts
      8
      Vehicles
      VW Golf 1.6 16v
      04-05-2011 06:25 PM #4
      I have a Mk4 Golf which is giving me the fault code P0171 too.. I have been to two different garage's to have this problem fixed & both times they replaced the lambda sensor / Oxygen sensor. After driving a mile down the road, both times the emmission workshop light comes back on.

      I gather the Cat converter could be another reason why I'm getting the P0171 fault code?

      If so why dont the fault code relate to the cat converter? Sorry I am a novice with cars

    5. Member ps2375's Avatar
      Join Date
      Aug 13th, 2003
      Location
      Meridian, ID
      Posts
      11,364
      Vehicles
      80 Rabbit(DEAD), 94 Golf
      04-05-2011 07:38 PM #5
      That code is generally a bad MAF. And I wouldn't let them change an O2 sensor unless there is a code for it.
      Tradition is the art of making the same mistake repeatedly, on purpose.

      FS:MkI low back front seat upholstery(new)

    6. n00b
      Join Date
      Mar 31st, 2011
      Posts
      8
      Vehicles
      VW Golf 1.6 16v
      04-06-2011 12:10 PM #6
      Quote Originally Posted by ps2375 View Post
      That code is generally a bad MAF. And I wouldn't let them change an O2 sensor unless there is a code for it.
      Would you suggest I change the air filter & also the Sensor?

    7. Member ps2375's Avatar
      Join Date
      Aug 13th, 2003
      Location
      Meridian, ID
      Posts
      11,364
      Vehicles
      80 Rabbit(DEAD), 94 Golf
      04-06-2011 07:18 PM #7
      Depend upon the age/condition of the filter, and I would get the code diagnosed by a competent shop.
      Tradition is the art of making the same mistake repeatedly, on purpose.

      FS:MkI low back front seat upholstery(new)

    8. n00b
      Join Date
      Mar 31st, 2011
      Posts
      8
      Vehicles
      VW Golf 1.6 16v
      04-06-2011 07:35 PM #8
      Ok Thanks you ps2375

    9. Member PBWB's Avatar
      Join Date
      Sep 12th, 2004
      Location
      NoVA
      Posts
      4,431
      Vehicles
      91 GTI ABA-T, 97 GTI VR, 06 MkIV Golf, 13 DE GTI, 13 Touareg TDI Executive Edition
      04-07-2011 07:36 AM #9
      My post is related to the possible cat issue, not the MAF code.

      My jetta had the guts blow out of it as well. There was one chunk left just big enough not to shoot out my straight through 2.5" exhaust, so I dropped the cat and broke it up and removed it. I still to this day haven't gotten an o2 sensor CEL.....but my car is "lucky and different".

      Your car could also be telling you it's a lean condition because of the wrong oxygen content in the exhaust flow and subsequently dumping fuel to compensate. This happens a lot with people running test pipes and such.

      But I agree, don't change an o2 sensor until you're either forced to or get a code for it.
      -Apple
      Articulated Speed Solutions FTW
      Quote Originally Posted by slcturbo View Post
      I dont care what you or anyone else "thinks" they have done. We're all just racing for fun on here whether you run 9's or 17's.

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •