1994 GMC Safari Repair Question
Failed etest new cat plugs wires caprotor pcv clean oil nox high co high hc very low should be 735 is 145
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??
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Problem was thermostat Stuck open engine running to cold for pcm's preference causing excess fuel problems.
Thanks, very much appreciated.
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