I failed the inspection for my nox (ppm) on my High Speed Emissions test. The standard is 1240 and my result was 1267.
Honda Q&AAsk Your Question
1994 Honda Civic Question: How can I lower my High Speed Nox (ppm)?
Answer #1Greg's Orange Auto (12262 Answers) , Orange, CA - (714) 361-9386globalhelper November 06, 2012, 12:44Master
ck egr passages for blockage of carbon or timing can be retarded or poss o2 sensor
Answer #2ziptie12 November 06, 2012, 19:24Master
Globalhelpers suggestion first!! EGR SYSTEM function is very important. Next would be timing as he mentioned , and then be sure the cooling system is in good shape. Last , if high miles (by age I'm assuming it is) maybe a top engine cleaner -get carbon build-up off pistons -lower comp. lower combustion temp=lower Nox.
Replyglobalhelper, November 06, 2012, 19:35Master
well said zip man
Replyziptie12, November 06, 2012, 21:05Master
Thank you.......:) ......never mind.
your.mechanic November 06, 2012, 20:20Master
Check EGR, and Carbon build-up