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Ok, my car failed the enhanced smog test in California. High NOx at 15mph (and near failing at 25mph)
California purch. 1986 740GLE Wagon, B230F Engine (non-turbo), 245K Miles (new catalytic converter 5 years ago)
I’ve read many posts here and elsewhere about typical reasons for high NOx (measures below). They include:
1. clogged /partially clogged EGR Valve, EGR pump, EGR pump hoses
2. a vacuum /vacuum hose leak
3. injector seal leaks
4. lean fuel condition (from bad O2 sensor)
5. clogged flame trap? (NOT SURE)
6. over advanced timing (or timing is off)
7. bad catalytic converter
I believe my engine (B230F) does not have an EGR system (even though it's a California purchased vehicle). The Haynes book is worthless for finding anything on the B230F engine, as it seems to focus on the 760Turbo.
While I am pretty much a novice in this area of maintenance I am willing to dive in. As another person said, “I would like to try the cheap/easiest stuff out first before I invest some serious money” Five dollars ($5) on a new Flame Trap? Sure. $200 on a new EGR Valve? Ouch!
To pass smog, one poster suggested it's the EGR valve (don't think I have one), another suggested using isopropyl alcohol (15% alc./85% gas), another suggested removing and cleaning the throttle body (??)... what to do?
Here are my test numbers:
15Mph (1769 RPM)
NOX (ppm) 1276 – 1125 max (399 avg) - FAILED barely
HC (ppm) 58 – 133 max (41 avg) – pass
CO (%) 0.39 – 0.82 max (0.13 avg) – pass
%CO2 – 14.7 – pass
%O2 – 0.3 – pass
25Mph (1810 RPM)
NOx (ppm) 935 – 955 max (332 avg) - passed barely
HC (ppm) 36 – 108 max (29 avg) – pass
CO (%) 0.32 – 0.62 max (0.11 avg) – pass
%CO2 – 14.8 – pass
%O2 – 0.2 – pass
Thanks in advance for the help. Hope this wasn’t an over-abundance of info.
Damien
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Similar posts:
[Great photos of all engines except mine. All non 740, non B230F engines]
EGR vs. Flame Trap; High NOX at emission test 200
http://www.brickboard.com/RWD/index.htm?id=704114
I Don’t Have an EGR (excessive NOx emissions -- no EGR 200 1992)
http://www.brickboard.com/RWD/index.htm?id=764876
4cyl EGR questions 200 1991
http://www.brickboard.com/RWD/index.htm?id=343012
EGR - Cleaning and removal instructions
http://www.volvospeed.com/Repair/egr.htm
VolvoClub & Brickboard FAQs posted the same EGR VALVE Service Requirements
http://brickboard.com/FAQ/700-900/EngineSensors.htm#EGRValve
Great Photo for ’92 240
http://www.brickboard.com/RWD/?id=620989
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Suggestions for passing CA Smog for high NOx [700][1986]