Ford Repair: Fails NO (Ohio e-check) - 1993 Taurus 3.0, exhaust gas analyzer, taurus 3

Question
Fails NO on Ohio e-check test.  Replaced all tune up parts, number went higher.
Any ideas?  Thank you

Answer
NO is controlled by 2 major parts on your car-- the EGR valve and the catalytic converter.  Either one could be failing.  If you're "close" to passing, a good dose of chevron injector cleaner may clean it up just enough.  EGR systems can clog, if that is the case it would have to be pulled apart and cleaned or replaced.  Unfortunately I can't tell you which one is the culprit-- only a shop with an exhaust gas analyzer can test this.  Hope this helps,
Jason