Wrong NOX an HC yes but not all of them! But on honda/acura the nox being high can also be just the cat..Not all cars has EGR valves either...)2 sensor will not make NOX be high only CO HC..And you cant clean a EGR valve an it be fixed you can clean the ports but if a egr is causing its b/c its bad...
Quote Originally Posted by CrbnIntegra
Start with the EGR, most can be cleaned without replacing it. Then check o2 sensors. You should know if the cat has gone bad, because all of your other numbers on the emissions test would have been high too.