Mechanics

FAILED TEST

1994 GMC Safari • 198,545 miles

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.
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Christrepanier
January 9, 2012.




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
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ASEMaster6371
Jan 10, 2012.
Problem was thermostat Stuck open engine running to cold for pcm's preference causing excess fuel problems.
Problem solved.
Thanks, very much appreciated.

Tiny
Christrepanier
Jan 11, 2012.

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