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passing emissions in Houston

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by trogdor4x4, Mar 6, 2004.

  1. trogdor4x4

    trogdor4x4 Registered Member

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    /forums/images/graemlins/confused.gifI failed (HC) emissions testing today, what can I do to pass?

    91 Stock 350, stock exhaust; replaced plugs, wires, cap, rotor bug, and changed oil last week.

    Test results:
    High Speed- Standard 126 current 180
    Low Speed- Standard 129 current 162

    What can I do to lower it?
    /forums/images/graemlins/confused.gif
    oh yeah, gas tank was almost empty (I don't know if that matters). Had to go straight to gas station.
     
  2. jakeslim

    jakeslim 1/2 ton status

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    I figure if I can dodge the law for 2 more years, I am home free in CA with my 77... /forums/images/graemlins/whistling.gif
     
  3. HarryH3

    HarryH3 1 ton status Author

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    High hydrocarbons is a sign of running rich or having a misfiring cylinder. An O2 sensor that is on the edge of failure could be the culprit. It also helps to take the rig out on a quick highway run and make sure that the engine is warmed up enough to be in closed loop mode and the cat is good and hot just before the test.
     
  4. K5Jimmy

    K5Jimmy 1/2 ton status

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    AC Delco O2 sensor....make sure you have a 195* thermostat...it cost me $75 diagnosis, $45 for an Autozone Bosch O2 sensor (fawked right outta the box), $40 for an AC DElco sensor that works...changed the EGR (on the advice of the testing station I'll Never go back to), and took the advise from this site to check for a 195* thermostat (had a 160) which was keeping it out of closed loop ($6 or so)...if I had asked here first, I woulda saved $135 or so.....BUT since I had it inspected, changed the EGR, took it back and failed...I had to take it to a Certified Inspection station where I got the straight skinny....I also had to pay for another inspection....Mines an 89 stock TBI with ceramic headers and duals (130K miles)...good luck... /forums/images/graemlins/thumb.gif
     
  5. trogdor4x4

    trogdor4x4 Registered Member

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    I changed the O2 sensor but can't get it tested until friday. It seems to idle smoother (I asume that made the difference) I also found that it was advanced to 2 degrees disconnected. I put it back to zero. I posted about plugs, I don't know if that will make any difference with the HC output. They are r43 delcos.
     
  6. trogdor4x4

    trogdor4x4 Registered Member

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    failed again, but a little closer
    I am going to go with the r45ts instead of the r43ts that I put in last week (that is what was called for as a stock replacement). Praying Hard.
     
  7. Tweetysuarus

    Tweetysuarus 1/2 ton status

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    Try this RxP ! I used this product both times in California to pass emissions test that I barely failed! Works great!
    Bill
     
  8. bigburban383

    bigburban383 1/2 ton status

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    Do an oil change(it works), fill up at a speedway (or gasihol station with 10% ether) and put a bottle of dry gas in. Make sure the truck is warmed up before hand when they do the test. Working EGR will bring your NOx readings down. Replace your O2, should be a 1 wire for its cheap.
     
  9. K5Jimmy

    K5Jimmy 1/2 ton status

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    So....How did ya make out with yer inspection? /forums/images/graemlins/thinking.gif
     
  10. trogdor4x4

    trogdor4x4 Registered Member

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    After trying small things and not passing, it ended up being my catylitic (?) converter needed to be replaced. went from about 170 to 44. wow. Thanks for all of the ideas.
     

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