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Ways to improve mpg

Discussion in 'Gen 2 Prius Fuel Economy' started by avoice217, Jul 20, 2022.

  1. avoice217

    avoice217 Member

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    2009 Prius
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    Ok so just a small update; just had a friend teach me how to replace the spark plugs. Good thing I asked him because I learned that there were a few tools that I didn't own & he just happened to have them. So now I'm set on that. Also I took the time to clean the throttle body. I'm so thankful I did because I was sure that it had never been cleaned in the past & I was indeed correct. When I started the brush was almost as black as one of those screens taking in the tar from nicotine in cigarettes. At the very end I ended up cleaning both sides 5x to ensure that I could get as much of that black junk as possible before it became too hot. Gonna test the car soon as I'm sure it'll run much faster. I noticed yesterday that the car was really difficult to just accelerate than normal & I knew that the spark plugs had to be replaced soon. I'm so thankful that's taken care of. Now I'll be fine with that until I graduate & then I'll be able to afford to upgrade to Toyota oem plugs.
     
  2. avoice217

    avoice217 Member

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    Hey all so here's my latest update. So I finally went & invested in the paid version of Dr Prius. When it came to the life expectancy test, I got stuck at the reverse part as it seems that the a/c kept interferring with the results. It did however post around 25%, which seems a little low to me. I also did try the full battery test, but that ended up being inconclusive as I wasn't able to get complete results. Despite trying to speed up & braking immediately 3x, the test wouldn't come to a 100% completion. I decided to take a screenshot of the car while in driving around. I did try to record the screen while driving around, but not really sure what happened to that file. I am planning on taking a full weekend in October to take the battery out & do some testing with the cells to get a better idea of just how many needs to be replaced. Aside from that, every single other maintenance based situation has been tended to.
     

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  3. dolj

    dolj Senior Member

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    Your battery temps are nonsensical. You need to check the temp sensor wire. Either that's broken somewhere or a temp sensor might be faulty.

    You probably won't get a good test with those temp readings.
     
  4. avoice217

    avoice217 Member

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    So based on what you're telling me is that I need to replace the hybrid temperature sensor? Just asking for clarification because online seems to tell me a couple of sensors, the other one being a coolant sensor. Just wanting to make sure that I order the correct sensor.
     
  5. dolj

    dolj Senior Member

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    I'm not actually telling to to replace anything. I'm pointing you at what you need to check. It is up to you if you want to unload the part cannon without checking anything.

    I'm not sure what "online" is saying, but you need to apply a little common sense. We're focused on the HV battery, so why would the coolant temperature sensor come up in conversation?

    There are three temperature sensors attached to the bottom of the HV battery. I'm not even sure you can buy the temperature sensor harness as a replacement part but to replace it you will need to do a decent amount of disassembly of the battery to replace it, so be sure you're up for it.