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Cell light PO172 PO172pd

Discussion in '1st Gen. Tacomas (1995-2004)' started by 1999tacotrd, Jun 28, 2009.

  1. Jun 28, 2009 at 11:05 PM
    #1
    1999tacotrd

    1999tacotrd [OP] 1999 Taco TRD xtracab 3.4 V6 4x4

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    I have these cell lights on and it says my truck is buring rich. I dont know what could cause it to do this i clean the MAF with Ele cleaner but did not help. It says on the odbII site that u cant tell much of a change in perfromance but i can cause when i goto take off from a dead stop the truck will bog down like it almost wants to die then i left off gas then push again and it takes off. Also when driveing down the highway 70 to 80 mph it gets a funny smell to it. The main thing is that scares me if i ever darted out and need to take off quick to avoid oncomeing trafic that bogging down could cause me to wreck. Any one here have any ideas how to fix it?
     
  2. Jul 2, 2009 at 6:18 PM
    #2
    kevhogaz

    kevhogaz Low Speed, High Drag

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    Air flow meter codes are tricky, since the description is backwards from the problem. Your truck is actually running lean, which is causing the bog. Too much fuel is going back to the tank, and not enough to the engine.

    Your air flow meter is the most likely culprit, as we see this all the time on Toyotas. Usually it's a P0171, which is system too lean.

    Check the obvious first, make sure your air hose that goes from the air cleaner housing to the throttle body didn't fall off, or is open at one end.

    If you've been cleaning your A/F meter, and it was giving you trouble in the past, it's more than likely time to replace it.

    Hope this helps.
     
  3. Jul 2, 2009 at 8:58 PM
    #3
    1999tacotrd

    1999tacotrd [OP] 1999 Taco TRD xtracab 3.4 V6 4x4

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    no the hose never fell off it gose from the filter to the throttle body

    and the air meter u mean the mass air flow sensor?
     
  4. Jul 2, 2009 at 9:26 PM
    #4
    kevhogaz

    kevhogaz Low Speed, High Drag

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    The air flow meter is sometimes referred to as a mass air flow meter. I suspect that's where your problem lies. Very common on Toyotas.
     
  5. Jul 3, 2009 at 2:23 PM
    #5
    1999tacotrd

    1999tacotrd [OP] 1999 Taco TRD xtracab 3.4 V6 4x4

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    What ever it is it makes the truck die some times. Can the MAF be tested before spending money on a new one?
     
  6. Jul 3, 2009 at 6:38 PM
    #6
    kevhogaz

    kevhogaz Low Speed, High Drag

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    Do you have a volt meter? It can be tested if you do.
     
  7. Jul 3, 2009 at 7:32 PM
    #7
    1999tacotrd

    1999tacotrd [OP] 1999 Taco TRD xtracab 3.4 V6 4x4

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    yeah got one but have no idea how to use it
     
  8. Jul 3, 2009 at 7:39 PM
    #8
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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  9. Jun 5, 2011 at 12:20 PM
    #9
    Bear2012

    Bear2012 Member

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    I have a 1999 Taco 3.4L V6 with only 140,000kms and about 4 months ago I got a check engine light in the dash, the truck ran like crap but bearable and took it to the garage near my work and they read the code as PO172 bank 1 too rich they checked fuel rail pressure, spark plugs but settled on the upstream O2 sensor they said was lazy and wanted $300+ to fix it, that included $220 for the sensor. I told them that was too expensive especially since I couls get a Denso O2 sensor on E-Bay for $70. So I paid for the diagnostic and ordered the sensor and installed it. three weeks ago the MIL came on again. I got stubborn, I wasn't going to take it back to the garage since they missdiagnosed the problem in the first place and I wasn't going to take it to the Stellership. I bid for and got a cheap OBDII code sensor on E-Bay for $53. Agian the Code read PO172 and I did some reserch on the net and this blog and found that actually that code does not piont toward a O2 sensor but main cuprit is the MAF sensor which I cleaned, end result Truck runs great. Hope this helps.
     
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