Time for emission test again. I took at look at my last one:
HC    5 / limit 58
CO    .01/limit .32
NO   354 / limit 435

Car has about 75k miles on it, driven only about 30 minutes a day at highway
speeds. Car was just serviced: new fuel filter, air filter. oil change, with
engine flush, new plugs, recent new DI casette, injector cleaning.  It still
has original Cat and O2 sensor.
I am curious if  it will fail the NO this time.  Anyone know what
contributes to NO increase??