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Failed Emissions (NOx) need help *FIXED*

Discussion in 'The Garage' started by greyhoundjc, Dec 6, 2006.

  1. greyhoundjc

    greyhoundjc 1/2 ton status

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    I just failed the state emissions in my 82 K5 with 350 motor and Holley Truck Avenger Carb/Holley intake manifold. The truck has a catalytic converter that appears to be fine. I bought it last year and all of the material is still intact inside. There is no EGR valve. The air pump has been disconnected by one of the previous owners. This is the last year that I have to fool with emissions on this truck, so any type of quick "band aids" in order to pass would be welcome.

    Test Results:

    25/25 Test 50/15 Test
    Reading Allowed Reading Allowed

    HC ppm 54 281 53 286
    CO% 0.03 2.26 0.02 1.64
    NOxppm 2520 1980 2928 2125
    RPM 1451 2500 max 1410 2500 max
    CO+CO2 11.9 6.0 min 12.4 6.0 min



     
    Last edited: Dec 7, 2006
  2. sandawgk5

    sandawgk5 3/4 ton status

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    I would say it needs the EGR and Airpump back on it.

    Ira
     
  3. SLOK5

    SLOK5 1/2 ton status

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    It will never pass without the air pump and egr disco......need air to get the cat hot enough to work....
     
  4. twoslo4five0

    twoslo4five0 3/4 ton status Premium Member GMOTM Winner

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    I Sure Am Gald We Do Not Have Emitions..
     
  5. MTChevy

    MTChevy 3/4 ton status Premium Member

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    EGR is the main part that reduces NOx emissions.
     
  6. greyhoundjc

    greyhoundjc 1/2 ton status

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    I do know that the EGR is pretty important. I've been able to pass the last two years without the EGR, but then they just did a 2 speed idle test. I've been to four different places and this year their pretty persistant about testing the truck on the dyno.
     
  7. K5MONSTERCHEV

    K5MONSTERCHEV 1/2 ton status

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    Heat is the cause of NOx. Check the timing, that will cause NOx too. The cat has to be good and hot before itll light off and work, was it cold when you took it to get tested?
     
  8. greyhoundjc

    greyhoundjc 1/2 ton status

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    The truck was up to operating temp, but I probably should have run it for longer than I did. Any idea of which way to go with the timing?
     
  9. K5MONSTERCHEV

    K5MONSTERCHEV 1/2 ton status

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    Well in CA we can only go +/- 3* form spec. Check the spec, check what it is, it might be too advanced.
     
  10. greyhoundjc

    greyhoundjc 1/2 ton status

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    Georgia has realitivly easy tests compared to other states. The only thing they visually inspect is to verify the cat is installed. So I can adjust the timing as much as necessary, I'm just not sure which way to go with it. The tag for my truck states 4* advanced. But that was for the 305 that it originally came with. I assume that the 350 is in the same neighborhood. The marks are hard to read, but I'm probably around 4-6* adv.
     
  11. greyhoundjc

    greyhoundjc 1/2 ton status

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    I passed the test today. I put 3 gallons of methanol in the tank with about 15 gallons of 93 octane gas. Passed with flying colors. It dropped the NOx down to 568 from 2520.
     
  12. wraenking

    wraenking 1/2 ton status

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    hmm. im having the same problem passing, except the last time i passed nox and failed co

    would this work for carbons also?

    where do you get methanol?

    thanks
     
  13. greyhoundjc

    greyhoundjc 1/2 ton status

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    It did lower all of my emissions, but the biggest difference by far was in the NOx. I found a place that sold different types of racing fuels and they had methanol. It was a little less than $5 per gallon. The guy at the place said that he sells alot of methanol to people trying to pass emissions.
     
  14. SLOK5

    SLOK5 1/2 ton status

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    Well at least its a BANDAID :D
     

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