Alright this one has been weird and frustrating. Got a ticket to see a referee. I had two appointments with state referee so far and today was my third appointment. First one=FAILED, Second one: Changed 02 Sensor=FAILED, Third one(Today): Changed Catalytic Converter= And of course still no pass=FAILED.

I will show the measures but let me start with what i have. Everything is basically stock:

1990 CRX SI
-SOHC ZC 1.6L -HEDMAN HEDDERS
-Reads 216,125 miles but doubt the ZC was the stock engine.

Done so far:

-New Dizzy Cap & Rotor, and ignition coil(the internal one in dizzy) -Spark Plugs (Ngk)
-Oil Change w/ Mobil Clean 5000 and added "Engine Restore"( this was before ticket, dont know if this matters or if it can affect the smog test being it suppose to restore compression and so on...)

HERE IS THE RESULTS:

<U>1ST TEST=*87 octane</U>


15MPH MAX/MEAS
RPM: 1858
HC: 142/109
CO: 0.86/0.25
NOX: 873/1200 FAIL

25MPH MAX/MEAS
RPM: 2027
HC: 117/97
CO: 0.76/0.25
NOX: 812/777

<U>SECOND TEST=*91 Octane</U>

15MPH MAX/MEAS
RPM: 1841
HC: 142/89
CO: 0.86/0.11
NOX: 873/1418 FAIL
*NOX numbers went up after New O2 sensor...The only difference besides O2 sensor being new I used 91 Octane instead 87(which I used for the first test) I believe this probably had something to do with measure going up.

25MPH MAX/MEAS
RPM: 1973
HC: 117/60
CO: 0.76/0.04
NOX: 812/797

<U>THIRD TEST=*With new CAT Converter and 87 Octane</U>

15MPH MAX/MEAS
RPM: 1860
HC: 142/30
CO: 0.86/0.09
NOX: 873/1242 FAIL

25MPH MAX/MEAS
RPM: 2025
HC: 117/15
CO: 0.76/0.03
NOX: 812/642


Please help guys, I am trying my best to search and check into other sources I may need all ideas and info that can help me detect why my 15 mph test still results in HIGH NOX, even after catalytic converter and new o2 sensors.
Thanks

 

EGR for sure nox is made by really hot hydrocarbons the egr cools down the combustion chamber and keeps nox down