Update:
Replaced all vacuum line fittings. Cleaned MAF. Checked for exhaust leaks (non). Just got back from another failed emissions test with the NO ppm well into the gross polluter category. Any ideas? Appreciate any suggestions. Contemplating a visit to an independent Volvo mechanic as I am out of ideas.
‘97 850na Wagon failed smog test
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SlowandSteady
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- Year and Model: 1997 850
- Location: Los Angeles
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abscate
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Nox high is a lean running condition. It is usually vacuum leaks that cause this, and smoke testing is the quick way to tHat out
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
Link to Maintenance record thread
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
Link to Maintenance record thread
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SlowandSteady
- Posts: 6
- Joined: 11 September 2024
- Year and Model: 1997 850
- Location: Los Angeles
- Has thanked: 1 time
Replaced all of the vacuum lines and the MAF with another Bosch unit that I sourced from a 97 at a scrapyard. Retest had my Nox drop significantly lower than the legal limit but my hydrocarbon numbers were now above of the legal limit…next I treated the fuel with some sea foam and replaced spark plugs….next retest both my Nox and HC numbers were well above legal limit. Any tips greatly appreciated.
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