I failed smog.
90 CRX Si. 180,060 miles, 100% stock, no mods, first failure.

Gas........ standard.......... reading
NOx....... 1839......... 1944 fail
HC......... 234......... 74 pass
CO........ 1.32.......... 0.48 pass
CO2................. 14. pass
O2................. .40 pass

The ref DID NOT put the dyno fan in front of car. When he did the pull, it went on automatically, but it was still on the side of the car, could this be the reason for the slightly high NOx reading?
I've read in other High Nox threads that some people say without the fan you'll get a high NOx reading.l
I don't want to start ripping the car apart and spending money needlesly, when it could just be he forgot to move the fan
Any ideas?

 

NOX is created when, when the car is being overheated, lean air/fuel mixtures, vacum leak, over advanced igintion timing and a defective EGR (exhaust gas reluctor). You might want to check them out if you cannot find out with is then your goin to have to take it to a specialist or shop who can isolate the nox with a 5 gas analizer.

 

the cooling will "might" help but only a little.

you want to pass that test retard the timing a few degrees and it will pass.

 

ttt