failed test

1994 GMC SAFARI
198,545 MILES
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CHRISTREPANIER
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1994 Safari - New cat plugs wires cap rotor pcv clean oil nox high co high HC very low should be 735 is 145 New cat plugs wires cap rotor pcv clean oil.
Jan 9, 2012 at 5:52 PM
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ASEMASTER6371
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do you have an egr valve?? with your mileage, carbon may be a factor causing the high nox.
what kind of cat did you use??

Roy
Jan 10, 2012 at 4:42 PM
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CHRISTREPANIER
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Problem was thermostat Stuck open engine running to cold for pcm's preference causing excess fuel problems.
Problem solved.
Thanks, very much appreciated.
Jan 11, 2012 at 12:31 AM
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