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2012 Toyota Sequoia Platinum Starting/Running Issues

Discussion in 'Sequoia 2nd Gen (2008-2022)' started by TheGense, Sep 4, 2021.

  1. Sep 4, 2021 at 12:09 PM
    #1
    TheGense

    TheGense [OP] New Member

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    Ok, I'm new here, though my husband has an account on TW, we've since sold our Taco and got my beloved Sequoia (along with a '97 Landy but that's a work in progress). Anyways, the Sequoia has run smoothly until a few days ago - I started it with the remote starter, after a few minutes it started to sputter and it turned off. Tried it again with the key in the ignition, same thing happened. Bare with me, fella Yota lovers, as I'm not a mechanic and only slightly mechanically inclined. If what I describe doesn't make sense, apologies

    It wasn't displaying the Check Engine light until after a few turn overs, plugged the OBD II sensor in and discovered cylinders 2, 4, 6 and 8 were misfiring. ONLY those cylinders, strange, right?

    We've replaced the fuel pump (with a tank full of gas ‍♀️) and still had the issue. He's tested the circuits of the Fuel Pump ECU and everything was normal.

    He doesn't seem to think it's the fuel or the fuel system, as all cylinders would misfire instead of one side?

    He's super frustrated, not only because he can't narrow it down but also because the underside is horribly rusted. No shops are available for a month or so, and this is our family mover. Though I am borrowing a family member's Toyota Camry which I'm thankful for.

    My husband has tried to narrow it down the best he could and I was wondering if anyone here could lend advice. He doesn't seem to think anyone would offer help, but I figured I check anyway.

    Thanks!
     
  2. Sep 4, 2021 at 12:44 PM
    #2
    frichco228

    frichco228 Valued Member

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    Eibach Pro Truck Stage 2 suspension, HD RAS, 285/75-18 Nokian Outpost AT, LoPro bed cover, TRD rear sway bar, DD 10 inch exhaust, and various other goodies
    How many miles? Up to date on maintenance? I'd disconnect battery, let it sit a bit to clear everything out. Then suggest you check condition of spark plugs and the coils. Your truck has some age so look for hairline cracks in the spark plug coils and if the plugs have 50k miles on them, may need replacement.

    Could be a bad cat converter on that side of truck also or maybe that O2 sensor.- Bank1 sensor 1. Bad 02 sensor will throw that exact error on that side.

    But I would check the coils and plugs first, if they are ok, test that o2 sensor and cat.
     
  3. Sep 4, 2021 at 1:10 PM
    #3
    Ericsopa

    Ericsopa Old man and the sea

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    Air injection pump system is divided, one for bank 1, one for bank 2. Could be a faulty pump, or relay, something stuck open causing problems with O2 sensor signals downstream on the one bank. Other things are divided between banks 1 & 2, such as variable valve timing sensors, cam timing oil control valves, and the O2 sensors themselves. Whatever your problem is, it appears to be something on one of these systems that are divided between left and right bank. Of course, I'd think that all those things should trigger additional codes, but it might well take more sophisticated diagnostic equipment than you have access to.
     
    Last edited: Sep 4, 2021
  4. Sep 4, 2021 at 6:37 PM
    #4
    TheGense

    TheGense [OP] New Member

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    **Update**

    It's no longer running a bank 2 failure - my husband replaced the fuel pump, and swapped O2 sensors. Replaced spark plugs, which showed that the truck was running lean on all cylinders. It also isn't showing any active codes anymore. However, it's still running lean, the AFR is still running in the 17s at idle. We heard what sounded like a sucking noise in the engine bay, right in the neck of the intake, but we couldn't find or pinpoint exactly what it was. My husband is still tinkering with it, endgame is him figuring it out or getting frustrated enough and waiting for a spot to open at a shop- which coincidentally are our only options :annoyed: :frusty:
     
  5. Sep 4, 2021 at 6:39 PM
    #5
    Ericsopa

    Ericsopa Old man and the sea

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    Mmm-hmm. Sounds like a vacuum leak in there somewhere.
     
    TheGense[OP] and THinTX like this.
  6. Sep 4, 2021 at 6:47 PM
    #6
    THinTX

    THinTX New Member

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    Agreed. Lean on both banks and you’re hearing a suction noise sounds like a vacuum leak. Check all hoses to and from the intake. Larger vacuum leaks can also cause higher than normal idle speeds. Warm idle should be in the 700RPM range.
    Could be hearing the Secondary Air pump too though.
    Also remove, inspect, and clean the MAF sensor.
     
    TheGense[OP] likes this.
  7. Sep 4, 2021 at 6:52 PM
    #7
    TheGense

    TheGense [OP] New Member

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    He did look at and clean the MAF. Will try to find the leak tomorrow, he's beat. Glad he has Labor day off, though hopefully we figure it out tomorrow so he can relax! Thanks for the responses, fellas. I really appreciate it. Will update if we find anything!
     
  8. Sep 4, 2021 at 7:32 PM
    #8
    TheGense

    TheGense [OP] New Member

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    Ok, one last thing to chew on tonight... readings from having it on just now.

    When the AFR goes to 18, fuel command attempts to go up and we lose vacuum. Something's switching on or opening to cause it to lose vacuum, bc it's instant.

    Ok, now a goodnight!

    Screenshot_20210904-221835.jpg
    Screenshot_20210904-221133.jpg
     
  9. Sep 9, 2021 at 11:46 AM
    #9
    TheGense

    TheGense [OP] New Member

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    After a few days, it was finally looked at at the Toyota Dealership. The tech told my husband it was the O2 sensors.

    Great, an easy fix! We had them ordered already and my husband put the new ones on when we got them.....and now it's running almost worse than before :confused::(

    I really want my truck back... I'm about to get a Haynes Manual and try to figure this sh!t out myself.
     
  10. Sep 12, 2021 at 8:41 AM
    #10
    TheGense

    TheGense [OP] New Member

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    Got my truck back yesterday! The issue was a bad Fuel Pump control module. We got a brand new and free fuel pump out of it too lol.

    I was happy to sit outside and look at my truck this morning while drinking my morning coffee.

    The funny thing is that they wanted to buy it from me. I guess stock is so low on Sequoias that they get alerted if one comes in to get fixed.

    The only way I'd agree is if I got another Sequoia, but there is such limited stock that I don't justify getting a 2017 or newer and paying 40k or more for nothing much that has changed other than adding LED headlights...

    We're planning on sandblasting the underbody and frame and fixing the rust. I'd be happy keeping this tough girl forever, to be honest!

    Thanks again for everyone's input! Now that she's fixed -- on to brainstorming mod ideas! :yes:
     
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