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Do I really need a secondary air pump?

Discussion in '5th Gen 4Runners (2010-2024)' started by RuggedJay, May 8, 2023.

  1. May 8, 2023 at 10:14 AM
    #1
    RuggedJay

    RuggedJay [OP] New Member

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    I recently bought a used early 5th gen 4runner.

    After looking under the hood more closely, I realized that this component as missing. The vehicle runs fine.

    Do I need to replace it? Is it an easy DIY job or do I have to pay a mechanic?(I'm cheap)
     
  2. May 8, 2023 at 10:18 AM
    #2
    whippersnapper02

    whippersnapper02 New Member

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    It won't pass smog if your state does it. Does it have a CEL on?
     
    jharkin likes this.
  3. May 8, 2023 at 10:32 AM
    #3
    RuggedJay

    RuggedJay [OP] New Member

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    Hmmm...I dont see a check engine light on. Previous owner also gave me the smog check form from 2 months ago and it passed on the form. This is a 2010 4runner with 150k miles
     
  4. May 8, 2023 at 1:01 PM
    #4
    Rocko9999

    Rocko9999 New Member

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    Do you have a code scanner? See if the codes were recently cleared. Regardless, go register it before that smog cert is invalid.
     
    kolter45 likes this.
  5. May 8, 2023 at 5:43 PM
    #5
    Startrek

    Startrek New Member

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    sec air inj pimp inst starts 2014
     
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  6. May 8, 2023 at 6:43 PM
    #6
    RuggedJay

    RuggedJay [OP] New Member

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    So if Secondary Air injection Pump wasnt originally part of my vehicle...does that mean I'm good???
     
  7. May 8, 2023 at 11:24 PM
    #7
    whippersnapper02

    whippersnapper02 New Member

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    Looks like @Startrek is correct. I know 14 was when the smog pump started for the Tacoma but I thought all 5th gen Runners had them. Here’s a 2010 Trail engine bay:

    IMG_1924.jpg

    https://youtu.be/dzvrOA0Dx_8
     
  8. May 9, 2023 at 8:22 AM
    #8
    Agent_Outside

    Agent_Outside A Guy A Girl and A Trail

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    No secondary air injection on early models.
     
  9. May 9, 2023 at 8:40 AM
    #9
    Slopemaster

    Slopemaster Slope Survivalist

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    It would be nice to be able to do a delete. I thought it’s main function was during engine start and shutdown. If that’s true, I don’t see how it would be detected during a smog check with engine running.
     
  10. May 9, 2023 at 8:47 AM
    #10
    Agent_Outside

    Agent_Outside A Guy A Girl and A Trail

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    Secondary air injects air into the exhaust so the cats heat up faster. A smog check doesn't check it directly, but the scan tool plug in does. You'd have faults stored for it and the readiness code would show incomplete/failed if you deleted it. You can tune the faults out and make the readiness bit read good 100% of the time but tuners have really cut down on that stuff as it's a federal offense to tamper with emissions and they are starting to crack down on tuners.
     
  11. May 9, 2023 at 9:11 AM
    #11
    Slopemaster

    Slopemaster Slope Survivalist

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    Thats good to know. Thank you.
     
  12. May 9, 2023 at 9:26 AM
    #12
    whippersnapper02

    whippersnapper02 New Member

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    There is a bypass out there. At least in CA, it wouldn't pass a visual. I was "failed" for a cracked cap and hose on my GTO. Really the guy just sent me to the store to buy a cap and he provided a new hose then passed me.
     
  13. May 9, 2023 at 4:48 PM
    #13
    RuggedJay

    RuggedJay [OP] New Member

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    Thanks for all the helpful responses everyone. I will watch the video.
     
  14. May 11, 2023 at 1:31 PM
    #14
    MAXIM

    MAXIM New Member

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    SAI sends ambient air from under the hood instead of intake air to exhaust while cats warming up is more accurate statement.
     
  15. May 11, 2023 at 7:39 PM
    #15
    Agent_Outside

    Agent_Outside A Guy A Girl and A Trail

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    I’m glad you specified it’s ambient air, that changes everything!
     
  16. May 11, 2023 at 7:57 PM
    #16
    MAXIM

    MAXIM New Member

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    It is not about ambient air but the fact SYSTEM DOES NOT "HEAT CATS FASTER" but rather introduces more air to reduce emission during start ups when engine runs rich. Don't get mad about someone trying get correct information out.
     
    POWERPLANTHOMER likes this.
  17. May 11, 2023 at 8:59 PM
    #17
    Agent_Outside

    Agent_Outside A Guy A Girl and A Trail

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    It absolutely heats the cats up faster. its meant to inject air to turn the cold start unburned/partially burnt fuel into a lean mixture that will get the burn hot in the cat to get it up to temp asap. I know this with absolute certainty, my literal job was quality testing and development of preproduction and prototype vehicles.
     
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  18. May 13, 2023 at 10:31 AM
    #18
    MAXIM

    MAXIM New Member

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    Makes sense. For that reason only I wouldn't install bypass. For those driving short trips unburned hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and particulate matter (PM) will add up quickly.
     

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