Toyota Repair: 96 Toyota Corolla - Failed CA SMOG Test, california smog test, combustion temperatures

Question
Hi, I have 96-Toyota Corolla, 1.8 L, 4 Cil. It has 105,000 miles. It recently failed California SMOG test (emission test). It Failed for NO (PPM). It failed because @15 mph, 1777 RPM, NO (PPM): MAX allowable=467 and MEAS (Amount measured)=1403. My engine light has been on about a month prior to the SMOG test. If you like, I could fax or email you the Smog check report. I appreciate any help. Thanks - Nick
Other info from SMOG test report:

@15mph, 1777 rmp;
CO2% = 14.50, O2 %=0.15;
HC(PPM) Max=61, AVE=9, MEAS=12;
CO% MAX=0.54, AVE=0.02, MEAS=0.43;
NO(PPM) MAX=467, AVE=57, MEAS=1403;
Result = FAIL

@25mph, 1812 rpm;
CO2%=14.7, O2%=0.04;
HC(PPM) MAX=45, AVE=7,MEAS=7;
CO% MAX=0.53, AVE=0.03, MEAS=0.45;
NO(PPM) MAX=754, AVE=50, MEAS=742;
Result =PASS

Note: MAX=Maximum Allowable Emission, AVE=Average Emission for passing, MEAS=Amount measured


Answer
I have looked at the readings and the good news is that the HC and CO amounts are good, this rules out a lot of things like an engine problem or catalityc converter failure.
The high NOx readings are caused by a malfunctioning EGR system, you said the check engine light has been on but to really help you I need to know what the trouble code is.
But I'm confident it is related to the EGR system(probably a DTC PO401) The egr system is designed to reduce combustion chamber temperatures which cause a reduction of the NOx gases, if the egr system is not functioning the combustion temperatures will rise and cause the check engine light to come on, the computer monitors the egr gas temperatures and if there is not enough gas flow will turn the light on.
You will need to have a repair shop test why this is happening, to test the system requires a vacuum gauge and pump, a scantool and someone that knows what they are doing.