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101k now / Never done any maintenence, now i'm getting poor mpg. What do I do?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 240sxer, Apr 5, 2010.

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  1. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I don't recall whether you had previously replaced the engine thermostat. That is a potential problem area if the thermostat sticks open. Then the engine doesn't have a chance to reach operating temp and consequently will operate more inefficiently.

    An instant read IR thermometer will show you the temperature of the thermostat housing. Operating temp should be around 185 degrees F.
     
    #81 Patrick Wong, Aug 24, 2010
  2. jayman

    jayman Senior Member

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    We appear to have covered all of the easy to do things. Another possibility is an O2 sensor starting to go bad, that will affect fuel economy long before a CEL is thrown. Could also be the traction battery is starting to age
     
    #82 jayman, Aug 24, 2010
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