C Cindy C New member Aug 13, 2013 #1 Ive been working on my car, changed cat, o2 sensor, erg valve, cleaned egr intake and much more i took it to smog and it failed due to high nox. What could be causing high nox?
Ive been working on my car, changed cat, o2 sensor, erg valve, cleaned egr intake and much more i took it to smog and it failed due to high nox. What could be causing high nox?
