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Gas Mileage

Discussion in '4th Gen 4Runners (2003-2009)' started by tomat2112, Mar 22, 2023.

  1. Mar 22, 2023 at 9:13 AM
    #1
    tomat2112

    tomat2112 [OP] New Member

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    First Name:
    Tom
    Vehicle:
    2006 Black 4Runner
    Hey all, first time posting. About a year ago I flashed a couple codes for bad O2 sensors, P0051 and P0036 in my '06 4runner sport V6 with 189k. It went away but having a 9-hour drive ahead of me during the summer I went ahead and had all 4 replaced. Ever since replacing them it seems like my mileage is down, averaging 240-270 miles per tank/15.4mpg combined. Maybe I'm just noticing more now with gas prices being what they are but the range at fill up always used to be around 350 Miles (I know this is not to be trusted and have heard it called the lie-o-meter) but now it's usually coming around 280-300 miles and I swear it's not as efficient as before the swap (drove from Richmond to D.C last week, burnt a half a tank on the way up and quarter tank on the way back, inconsistent). I've cleaned the MAF sensor, changed the air filter, reset the computer, had it hooked to the diagnostic machine and no vacuum leaks or other red flags, runs as well as ever. I've considered changing the MAF sensor but have no codes and it's not a cheap part (especially from Toyota). Am I overthinking and that's just the way it is or does anyone have any thoughts? Have also considered going to the junkyard and getting a MAF sensor from a late model Toyota just to see what happens. Thanks in advance for any input.
     
  2. Mar 22, 2023 at 11:17 AM
    #2
    xtremewlr

    xtremewlr New Member

    Joined:
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    Todd
    Tucson, AZ
    Vehicle:
    2003 4Runner V8 Limited 4WD
    Lots with more in the works
    So many possible things could contribute to this. I doubt changing the MAF will make a difference and I would never get a junkyard one. You cleaned it, leave it be.

    Has the air filter been changed recently?
    Have the spark plugs been changed or maybe they are due for a change?
    Have you verified air pressure in the tires is where it should be?
    Are you using the same gas brand/station/pump as you usually do?
    Did you recently add something to the truck, like a roof rack or armored bumper, that might have added more wind resistance or weight?

    Rule out the basics first, such as all regular maintenance is done.
     
  3. Mar 22, 2023 at 11:32 AM
    #3
    tomat2112

    tomat2112 [OP] New Member

    Joined:
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    Male
    First Name:
    Tom
    Vehicle:
    2006 Black 4Runner
    Air filter has been done recently,
    Installed iridium plugs and new wires 60k ago,
    Tire pressure is good, running on Michelins,
    Same gas as ever,
    No new equipment which would alter wind resistance.

    Hell I even waxed it last month, that should add at least a couple MPG, right LOL?

    I am due for an oil change but am regular on that. I do have a coolant leak I have yet to identify though, potential culprit?
     
  4. Mar 22, 2023 at 2:16 PM
    #4
    xtremewlr

    xtremewlr New Member

    Joined:
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    Gender:
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    First Name:
    Todd
    Tucson, AZ
    Vehicle:
    2003 4Runner V8 Limited 4WD
    Lots with more in the works
    I run Iridiums in my V8 4runner and change them at 50k. Just what I do but you could try changing plugs with a fresh set.

    Coolant leak would not contribute to decreased gas mileage.
     
  5. Mar 23, 2023 at 11:40 AM
    #5
    tomat2112

    tomat2112 [OP] New Member

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    First Name:
    Tom
    Vehicle:
    2006 Black 4Runner
    Thanks for the input, I'll put plugs on my list. Curious, what kind of mileage do you get in the V8?
     
  6. Mar 23, 2023 at 2:25 PM
    #6
    xtremewlr

    xtremewlr New Member

    Joined:
    Oct 10, 2020
    Member:
    #17247
    Messages:
    401
    Gender:
    Male
    First Name:
    Todd
    Tucson, AZ
    Vehicle:
    2003 4Runner V8 Limited 4WD
    Lots with more in the works
    Currently get 16-17 on average, driving around town and commuting to and from work on the freeway. About 50 miles round trip, mainly freeway but about 10 miles on surface streets.

    Pure freeway driving varies and is usually slightly lower for me. I've got a fair amount of added weight with the steel front and rear bumpers and I'm also lifted with 285/70/17 tires. Bigger tires that are really exposed don't equate to great gas mileage. So that will vary from 14 to 17-ish, depending on how much uphill is on the trip.
     

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