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1999 Volkswagen Beetle Question: Is there a difference between a charcoal canister & a Evap. canister?

 

Question

jodiravin, 2.0L 4 Cylinder, Sherman Oaks, CA, March 10, 2010, 17:36
 Rookie

I failed a smog test and was told I needed an evap canister and a Mass Air Flow Sensor. I would like to buy these parts myself due to the cost. I don't know where to buy them Can something be repaired instead of buying the new parts? I don't have alot of cash at this time.
Thanks

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  • Answer #1

    Bret Bodas from RepairPal Test Shop, March 10, 2010, 17:49
     Master

    They are the same part. Did the shop say why both of these need to be replaced? Was your check engine light on? If so, do you know the codes that were stored?
    I'm suspicious of this diagnosis...

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    jodiravin, March 10, 2010, 23:57
     Rookie

    I'm so confused.
    What he said is since my check engine light is on, diagnosis code
    PO455-Large Fuel Evap. Leak. Trace problem to broken Evap. Canister.
    Is that the same as Charcoal Canister, which is what he said I need? Also he said:
    PO1582-Fuel Adapt.at limit. Need to replace Mass Air Flow Sensor.
    HELP

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    Bret Bodas, March 11, 2010, 09:09
     Master

    Let me see if I can help clear some of this up.

    P0455 Code: If the Evap. canister is broken, it will be obvious and they can show it to you. Ask them to show so you can verify this before replacing it.
    Yes, the Charcoal and Evap. canister are the same part.

    Below is the information for the P1582 code, it is quite technical but what it is saying is this. "The engine idle speed is controlled by the throttle body, and the throttle body can adapt to things that try to make the idle speed too high or too low. It will adapt only so much and if it has goes beyond a specified point, the P1582 code is stored."

    The "Causes" section mentions hoses in the Evap system, so the broken Evap canister can possibly cause this code to occur, therefore not needing the Mass Airflow Sensor. As a matter of fact, I don't see mass airflow sensor on the list of possible causes so I wonder how they came to that conclusion.

    P1582 - Key on or engine running, the ECM (Engine Control Module) detected that the idle adaptation reached its limit.
    Possible Causes:
    -Crankcase oil is diluted (change the oil)
    -Fuel injectors are worn
    -Compression ratio is low
    -Throttle valve control module is faulty
    -Leak Detection Pump has failed
    ***EVAP canister system has an improper or broken seal***
    ***Evaporative Emission (EVAP) canister purge regulator valve 1 is faulty***
    ***Hoses between the fuel pump and the EVAP canister are faulty***
    -Fuel filler cap is loose
    -Fuel pump seal is defective, faulty or otherwise leaking
    ***Hoses between the EVAP canister and the fuel flap unit are faulty***
    ***Hoses between the EVAP canister and the evaporative emission canister purge***
    -regulator valve are faulty
    -ECM has failed

    In the end, I would replace the broken Evap canister only, then check to see that all the diagnostic tests pass.

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    Visitor, November 14, 2010, 16:38

    Is there a site that will show me what these parts look like?

    Thank you

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