Join Date: Jul 2002
Location: Washington D.C. Area (MoCo, MD)
Feedback Score: 5 reviews
My state don't required NOx anymore it was only for OBD0 and OBD1 and never on the OBD2. Since my state put those cars thru the rollers but now they don't use it anymore. All OBD2 they just scan it thru the OBD port.
They did have to do the NOx on my 1994 Jeep but this was over 20 years ago. If I remember correctly I was failing the SMOG test and not the NOx. I put in the BGE to clean out the motor (4.0L, I6) it lowered the SMOG where it pass but raised up the NOx and failed.
What cause NOx to fail emission has to do with vacuum leak/s and/or defective fuel control components, such as the Air Flow Meter, Engine Coolant Temperature Sensor, and O2 sensors.
Last edited by phatintegra; 02-06-2019 at 06:03 AM.