1994 Honda Civic Q&A

1994 Honda Civic Question: How can I lower my High Speed Nox (ppm)?

I failed the inspection for my nox (ppm) on my High Speed Emissions test. The standard is 1240 and my result was 1267. -
Answer 1
ck egr passages for blockage of carbon or timing can be retarded or poss o2 sensor -
Answer 2
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. -
Comment 1
well said zip man -
Comment 2
Thank you.......:) ......never mind. -
Answer 3
Check EGR, and Carbon build-up -