High NO reading on Smog Test?

[bates]

Does anyone know what causes a high NO reading on a CA Smog test?

I took my car (2000 Acura Integra LS)in for its' preregistration renewal smog test last weekend. I had to go to a Test Only station per the renewal notice. When the car was tested it came out just a few parts per million below the nearly 500 that were acceptable for the 15 MPH NO reading. The 25 MPH readings were something around 17 PPM out of an allowable 500 or so. The engine RPM was within 50 RPM or so due to gearing. What I'd like to know is if anyone knows what causes a high NO reading and if there is something I can do or replace to decrease the near failing values. The Smog Tech couldn't or wouldn't tell me anything answering only "I just test them, I don't know why they come out the way that they do, all I care about is seeing that the car passed."

I'd like to repair the engine or emissions control system to make it work better, burn cleaner, and reduce the emissions but don't have any idea where to start. Any suggestions or help would be greatly appreciated.