Smog test curiosity
 

I was randomly picked to do Calif emissions test for the 2nd year in a row, it passed but I'm confused.

The test results are dramatically better this year - 1/2 of the HC emissions, 1/3 of the CO, and 1/2 of the NO.

The only thing I really did to the powertrain performance wise since the prior tests was I removed the stock muffler and put on a straight through glass pack. Same CAT is in place.

Does a more free flowing exhaust make it run cleaner?

what do you mean by randomly picked?
is this in addition to the already required smog checks?
i've had to have test only smog checks since i got the car ( it's always passed with flying colors), i've also heard if a type of car has a history of failures, then that entire group is placed in the gross polluter list.

It was done in 2006 & 2008, I wasn't due until 2010 but I got notice to go to a test only station for 2009. I called DMV and asked why and was told they do a random test of 2% of vehicles or I could be in the list of gross polluter vehicles.

Passing wasn't a problem, but I had to argue with testers that it was still a street legal car and had to go to 3 places to before finding someone who could get in the car with a full roll cage.

on one smog check, I argued for 20 min that i had illegally modified the car because it didn't have a smog pump.
It took the "tech" 20 min of calling around to find out what i already told him, what a dumbass, he never even apologized for accusing me of the illegal mod.

smog tests are a joke.

I was accused of modifying an 86 Chevy pickup I had in California. It wasn't even a California vehicle and it took me three days to get the paperwork together to prove where I bought it, when I bought it, who I bought it from, how far I drove it when I moved, etc, etc, etc. What a crock, it ran cleaner than the '98 California cars.

But, California likes to train people to kill themselves on motorcycles too - long story. :)