Smog test results, and the meaning

CHEVROLET TAHOE
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MIKESANJOSE
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I have a 97 Tahoe with 119K and have taken pretty good care of it since it was new. Just had it smogged under California's Enhanced program. It passed, but all the numbers were well above the "Average" and about 70% of the maximum. HC (measured 71;max of 103) CO (measured .47; max .58) NO (measured 623; max 986). It's due for a tune-up but do these numbers imply a bigger engine problem then a simple tune-up? Valve job perhaps?
Aug 27, 2007 at 8:26 AM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
[quote:6a78268665="mikesanjose"]I have a 97 Tahoe with 119K and have taken pretty good care of it since it was new. Just had it smogged under California's Enhanced program. It passed, but all the numbers were well above the "Average" and about 70% of the maximum. HC (measured 71;max of 103) CO (measured .47; max .58) NO (measured 623; max 986). It's due for a tune-up but do these numbers imply a bigger engine problem then a simple tune-up? Valve job perhaps?[/quote:6a78268665]

Give it a major tune-up-the only thing I see is partly burn fuel- and change your oil.
Aug 27, 2007 at 8:39 AM
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