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Emissions problem, 90 Si with '89 ZC

Discussion in 'General Tech and Maintenance' started by 90SiZC, Nov 6, 2006.

  1. 90SiZC

    90SiZC Junior Member

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    Just got back from my local emissions test. HC was ok, CO waaay low... but I got killed on the NOx reading. No, not nitrous oxide. ;)

    Any good suggestions for things to look for, check etc?

    The car: 1990 Honda Civic Si
    The engine: 1989 JDM Civic ZC
    The ECU: 1989 Integra 5 speed

    I don't have my manual here to see what the factory recommended. But I am in a crunch as I have to pass before Wednesday when I head to court to explain why the car hasn't been inspected in years..


    TIA

    Jim
     
  2. jlicrx

    jlicrx Senior Member

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    high NOx readings caused by extremely high combustion chamber temperatures - usual causes are engine running too lean, ignition timing advanced too far or faulty catalytic converter
     
  3. jlicrx

    jlicrx Senior Member

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    make sure the cat and engine are really warm before testing it - take it out and run it hard right before testing
     
  4. 90SiZC

    90SiZC Junior Member

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    I'll do what I can about the warm up... it's a private service station so I takes my chances on when they'll get to me. Today there was no one in line so it was actually pretty quick.

    And I suppose 200k miles is too many for the factory cat? Especially since I finally cleared up the temp sensor issue that was dumping waaaay too much gas on occasion.

    Thanks,

    Jim
     
  5. 90SiZC

    90SiZC Junior Member

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    Yeah... I only went to this place because it was close to work so I could do it over lunch time. There's a chain of Kwik Kar places in Texas... there's another shop that's "Honda friendly", but 3 towns away.
     
  6. 90SiZC

    90SiZC Junior Member

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    North Texas.

    The only problem with changing shops is the $39.50 fee each one charges for the inspection.

    I get one free retest at the first set of yahoos then it's open.

    New cat is on the way, I'll put that on, tweak the timing and keep my fingers closed. My '89 Teg used to pass easily despite burning 1 qt of oil every 100 miles.
     
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