So my smog passed with flying colors, go figure since i'm still stock, but one number jumped out at me, avg in cali for hc at 2500 rpm is like 12ppm and i was up at 18ppm. Now i'm a bit worried that this is the beginning trend of a failed smog in 2 years, so i'm wondering, anyone know what could cause it to be so high? I know subies run rich, especially the n/a ones like mine pushing 10 to 1 compression on crappy 87 octane, could this be the cause, or should i look deeper in, maybe at my cats?

 

no u should not worry about it. HC is hydrocarbon which is unburn fuel.
i mean u measured 18ppm so it's not like its alot. it's only 6ppm more then the average.
as a subaru owner i would not worry about smog really cuz we will never see a dyno to simulate load condition's to where our HC,CO,O2 to be dramatic, and ur car is all stock.
but Nox's on the other hand is what i worry about.
as long as u do your regular services u shouldn't have to worry about it too much.
as for the cat i wouldnt change it. and 6ppm isn't high at all imo.
every car is different. and as for the average thats just that, the average of hundred's of car's taken and averaged back out to make the state's standard's.
just wondering what's the max for your car?
HC:
CO:
o2:
Nox:

 

HC at idle is 100 ppm max. 17 avg, i put up 9
HC at 2500 is 130 ppm max, 12 avg, i put up 18

Co2 is max 1% at idle and 2500 rpm, i put up .01% and .01% respectivley

O2 did not give me a max on the test, just a measurement, .1% for both

No NOX on my printout sheet, CO2 was just a measurement as well, 14.9% at idle and 14.8% at 2500 rpm was my results there.

 

with the max posted i would not worry too much about it.
i mean at idle max is 100ppm and u measured 9ppm and at 2500 is 130ppm and u only put out 18ppm.
your Co2 and O2 is where it need's to be. no leaks, so thats good.
i would not worry about it too much as i said b4 every car is different and the average is a bunch of car's smoged and then averaged back out for the state's standard.
i've seen alot of reading's and your's are clean.
and should stay that way since its stock w/o mod's.
just do your regular services and it'll last you a very long time.