Solved my bad MPG

Discussion in 'Gen 2 Prius Fuel Economy' started by JC91006, Nov 13, 2017.

  1. audiodave

    audiodave Member

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    Cleaning the maf sensor and throttle body could change things too.

    Posted via the PriusChat mobile app.
     
  2. JC91006

    JC91006 Senior Member

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    My car's mpg is still not up to where my other gen2 cars are at, I'm going to swap the MAF sensor from my 50mpg gen2 and see if anything changes.
     
  3. Mendel Leisk

    Mendel Leisk Lapsed Cargo Cultist

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    Are they the same physically? Interesting. Hopefully same internally as well.
     
  4. JC91006

    JC91006 Senior Member

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    Both are identical, 2005 package 2.

    The lower mileage one is the one with the lower mpg. Only 113000 miles. The one with 190000 gets 50mpg
     
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  5. JC91006

    JC91006 Senior Member

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    Swapped the MAF sensors today. Initial test drives were very positive, low 50mpg on both cars. Now this is strange....

    I'll drive them for a week and see what happens after a few hundred miles.
     
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  6. audiodave

    audiodave Member

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    I changed mine and it didn't help. Got the best mileage with a dirty air filter, dirty t body and old sensor. Lol
    235,000 miles.

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  7. audiodave

    audiodave Member

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    I suspect if you had reset the computer it just needs time to settle to low 40's mpg again.
    I'm ready to change my injectors and O2 sensor. Low 40's is alI get.

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  8. audiodave

    audiodave Member

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    Maybe that upstream o2 sensor is a little off. Thinking of changing mine. I'm sure it's efficiency is off after 236,000 miles.

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  9. milestoempty

    milestoempty Junior Member

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    Watching this...

    Just replaced the 12v battery in my car 2 months ago. Two weeks ago I did an oil change, air filter, and cleaned the MAF (111k) and now Im averaging 43k miles down from 49. Replaced my plugs about 20k miles ago.
     
  10. JC91006

    JC91006 Senior Member

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    How's your tires and alignment?
     
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  11. audiodave

    audiodave Member

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    How many tanks of gas have you ran through? Assuming computer was reset.

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  12. audiodave

    audiodave Member

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  13. Suzan OBrien

    Suzan OBrien New Member

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    I was having horrible MPG... and still do. About a year ago I put in Platinum plugs hoping that would help, but it' didn't. I am getting 40 at 144K and good maintenance.
     
  14. Mavi

    Mavi Member

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    Any update? My prius is now down to 39mpg, while my brothers gets 44 same conditions throughout. So trying to figure out why. Also noticing some knock.
    Using the SK16R11
     
  15. JC91006

    JC91006 Senior Member

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    I find most of my local driving is still on the lower mpg side. I attribute that to the 17" tires. On the highway, I avg close to 47mpg.

    I'm not sure if the spark plugs change did anything as local driving mpg is still around 41 mpg
     
  16. audiodave

    audiodave Member

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    Same with me, higher mileage on the highway than around town. Low 40's to high 40's on the highway. 237,000 miles on 15 inch wheels.

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  17. JC91006

    JC91006 Senior Member

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    On my other cars with 15" tires I avg over 45mpg no matter if I drive local or highway
     
  18. audiodave

    audiodave Member

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    Well most of my around town driving is short trips and cold starts. So the worst of milage.

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  19. Erik Owens

    Erik Owens Member

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    I know it is always wisest to check the engine components to fix issues with MPG but being a hybrid I would always check to see if they HV battery is doing well also. MPG can suffer on the engine side and also the HV Battery side mainly where the battery cell connections are bolted together. They can be corroded and/ or the battery can be slowly starting to discharge intermittently.
    Not to say that your main issue being your plugs but as always keep it in the back of your mind. 2005 model. Possibly past 100K like I have read. Plus Iridium shouldnt need to be gapped but plugs do depend on resistance and type of course.
     
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  20. audiodave

    audiodave Member

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    Curious on the plugs, gap was not correct on mine. They needed to be gapped. 43 is a number not every gapper has.

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