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hydrocarbons at idle failed

Discussion in 'General Chevy & GM Tech Questions' started by 93pacetruck, Apr 14, 2013.

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  1. 93pacetruck

    93pacetruck New Member

    Hello all, I have a 93 5.7 with 161K on it and it failed emissions for hydrocarbons too high at idle. At 2500 rpm it passed ok. Truck runs pretty good but has only been driven 5-7000 miles in last 5 years. It doesnt run rich or have any odd odors and the cat temp is only 50 deg difference front to rear so it seems to be flowing ok. I know it needs a tune up since it has probably been 7-9 years. Besides the tune-up and timing set, is there anything else I should be checking for? Appreciate any help I get. Thanks
  2. Enkeiavalanche

    Enkeiavalanche Rockstar 4 Years ROTM Winner 5000 Posts

    Try some Seafoam or something to clean out the motor.. Where in NJ are you?
  3. 93pacetruck

    93pacetruck New Member

    southern Nj Sicklerville
  4. Enkeiavalanche

    Enkeiavalanche Rockstar 4 Years ROTM Winner 5000 Posts

    Nice I'll be in that area soon on the Wadding River...in Chatsworth
  5. 93pacetruck

    93pacetruck New Member

    Get some fresh cranberries when you are there
  6. Enkeiavalanche

    Enkeiavalanche Rockstar 4 Years ROTM Winner 5000 Posts

    You bet but they are not out yet.. You should come There is a post about it in the NJ area.. Did you try to clean out the motor?
  7. 93pacetruck

    93pacetruck New Member

    I haven't tried anything yet just trying to get some responses and see if there is a consensus on some ideas such as the seafoam treatment. I will probably do that first before I do the tune up but I am trying to find out if there are any electrical items like sensors that I should be aware of. I think the o2 sensor is ok because it is fine once it gets off idle. I'm suspecting the tuneup is going to be the biggest cure but just covering my bases
  8. yotchie

    yotchie Rockstar 100 Posts

    once you have done the seafoam i would do a good tune up. personally i would change the 02 sensors. sometimes better safe than sorry
  9. 93pacetruck

    93pacetruck New Member

    Thanks for the reply
  10. Opiewho

    Opiewho Member

    Tune up first, then check for vacuum leaks.

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