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Help with P0420 fault code

armstrong_21490 Jul 30, 2014

  1. armstrong_21490

    armstrong_21490 Member

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    I am getting the following fault code p0420 catalyst system below threshold

    I was wondering if anyone has had any dealings with this code and what is causing it?

    I have cleared the code but it comes back on after a while.

    Cheers

    Ross
     
    Last edited: Jul 30, 2014
  2. mechanic69

    mechanic69 Well-Known Member VCDS Map User Gold Supporter Audi S3 DSG

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    Ross-Tech Wiki post this info:

    16786/P0402/001026 - Exhaust Gas Recirculation (EGR): Excessive Flow

    Possible Symptoms
    Malfunction Indicator Light (MIL) ON
    Reduced Exhaust Gas Recirculation (EGR)
    Reduced Power Output/Engine running rough
    Increased Emissions

    Possible Causes
    Exhaust Gas Recirculation (EGR) Valve stuck open/leaking/faulty
    Exhaust Gas Recirculation (EGR) System leaking/faulty
    Wiring and/or Connector(s) from/to Exhaust Gas Recirculation (EGR) Valve faulty
    Possible Solutions

    Check/Clean Exhaust Gas Recirculation (EGR) System
    Check/Replace Exhaust Gas Recirculation (EGR) Valve
    Check Wiring and/or Connector(s) from/to Exhaust Gas Recirculation (EGR) Valve
     
  3. armstrong_21490

    armstrong_21490 Member

    87
    15
    8
    Sorry bud I just realised i had put the wrong code in the title. I've changed it now.
     

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