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headers

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by therover87, Jan 6, 2002.

  1. therover87

    therover87 1/2 ton status

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    i have an 87 k5 blazer and i was looking to get some headers, but my question is on my truck now i have the a.i.r. tubes but i took the cats off so if i buy a header it doesn't have to have the air tubes right?, and will the computer function properly with out them, cause i dont have the cats so i don't see a point to having them, hopefully someone can clear this up for me, thanks.
     
  2. txbartman

    txbartman 1/2 ton status

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    I have an 85, which is a bit different from yours emissions wise. But, let's make things simple. If you took your cats off, you are not emissions legal. So, not having AIR and your smog pump won't make things any worse. Still not legal. So, I would say lose'm.

    Mine doesn't have a computer, but I don't know if it will impact yours. If you decide to put your headers back on, your AIR has nothing to do with your cats. (from my understanding per my manual, but maybe that's just my year model)

    Brian
    Check out <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Jimmy</a> with all her projects!
     
  3. WARP1

    WARP1 Registered Member

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    I put headers on my '73 Blazer which of'course has no computer. I used the exhaust system from JC Whitney. It didn't bolt-in as advertised. It required several extra S-shaped pipes from AutoZone to even fit. And it is still going to need to be welded up to stop the exhaust leaks.

    On the emissions stuff I have a '93 Mustang with a computer, aftermarket (long tube) headers, an air pump, and no cats. Everything I say is from my Mustang experience but it might relate your Blazer. There is no problem with the short style headers, many are even emissions legal. With the long headers there is a concern that the O2 sensor has been moved further down the exhaust stream and that could cause it to be cooler than normal and cause your car(truck) to run lean. My personal experience my car runs great on the highway (24-25mph with a 340hp V8) but smells like gas around town (but I do have a loppy cam that could be the cause of that). I have never seen any evidence that the O2 sensor relocation does or doesn't cause a problem.

    '73 Blazer, 4" lift, 33" BFG Muds
     
  4. therover87

    therover87 1/2 ton status

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    has anyone else done this before and will it affect the ecm?
     
  5. CaptCrunch

    CaptCrunch 1/2 ton status

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    None of the emissions stuff will effect the computer. It may effect you emissions thought depending what you do. My 87 has all of it gone... cats and all and have no problems. But we don't have emission testing here anymore either.

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <a target="_blank" href=http://coloradok5.com/gallery/captcrunch>http://coloradok5.com/gallery/captcrunch</a>
     

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