[SentraSE-R]

It's been a long time since I did NICE-on P&G, but IIRC, I got mid-40s mpg averaging ~30 mph. I got mid-50s mpg @32 mph in 5th gear cruise control on the same drive.

Are the data there to support an assumption that my engine is an average polluter when run normally (smog test 3)?

Are there any alternate theories with equal likelihood to dethrone P&G from being the cause of the above-average air pollution test results? I realize 4 months of relative inactivity, or one month of complete inactivity alone could be the cause, but given my P&G history, and the return to normal HC results after my 900 mile "normal" driving, is there another theory with equal likelihood?

Does anyone see any major logic flaw in my suspicion that I'm dumping 15-75X the average xB's HC into the air with unlit cat P&G? FWIW, my constantly-lit-cat drive today saw the cat temps staying between 985 and 1339 degrees F.

Mech, I was driving 100 miles/night looking for rattlesnakes in the desert when I was that age. Gas was 18.9 cents/gallon. Life was good. When I was younger, midday LA smog looked like nighttime Central Valley Tule Fog. We'd play touch football in air so foul, it gave us shortness of breath. I don't want my gaming behavior to swing us back in that direction.

dcb, I wish I could make more sense out of those data. The NOx spike seems strange. I'm happy to see the HC back to normal.

I P&Ged, I failed to light the cat, and my emission values were abnormally high.

I lit the cat for 100 miles, my emission values dropped, and were still abnormally high.

I lit the cat for 900 miles, my emission values returned to normal. Is there any other cause and effect relationship going on here?