Whoa back up the bus here.
HC means gas is not burning, not that its rich.
CO indicates a rich condition. When CO is high HC will natrually follow as it will have to much to burn.
NOx means you have a high temp in the combustion chamber, Having timing to far advanced will cause this temp to go up. He didnt just fail you for your readings, He also failed you for timing and for your gas cap. When you buy a cap stick with factory . The after market ones dont last long.A good point brought up is the car ebeing warmed up properly. Your 15mph reading on your CO in conjunction with the other readings at 15mph indicates the car might not have been fully warmed up. As a refferee station tech he should know he has to make sure its at full op temp. Reset your timing and have it rechecked.
Why are you going to a refferre to begin with? Did you Gross pollute prior or did you get a test only stamp on your registration?
