Just did smog check and barely pass, here is the result:

15mph - 1813 rpm
CO2% 15.3
O2% 20.6
Max Avg Meas Type
61 9 61 HC
0.54 0.02 0.43 CO
467 57 386 NO

25mph - 1877 rpm
CO2% 15.3
O2% 20.6
Max Avg Meas Type
45 7 26 HC
0.53 0.03 0.07 CO
754 50 231 NO

Just did a tune up 1500 miles ago and a spark plug change. So I am lucky that I barely pass the 15mph HC, and everything else is getting up there. Now what I don't understand is why every one else have almost zero on O2 and I have 20%, isn't air only 23% O2? Does that means I am leaking like crazy?

Oh yeah, it is an LS auto with 150k miles on it.

 

Just looked on google, atmosphere only has 20.7% O2 and that ideal burn CO2 is 15.5%, it is clearly the smog shop I went to has a modded smog machine that try to get around those 2 number, seems like only HC, CO, and NO is read here.

 

the machine they were useing could probably be out of calabration. just ingore the O2% values and just worry about you CO% which looks pretty rich........

i would say its possible your o2 sensor is not working or they didnt properly warm the car/converter up prior to the test.