Lately, you may have noticed the coastal elites in the press have picked up on the trend of hicks modifying their trucks to "roll coal."
Normally, I'd leave that stuff for the Truck Yeah folks. But lately I've noticed a lot of enthusiasm on Jalopnik and Oppo for "straight pipe/cat delete" exhaust systems. And I have to admit that I've been laughing maniacally at all manner of strange beasts running straight pipes: an S80 V8, former "country club special" LS430s, Toyota 4Runners, you name it. It sounds good with a bent-8 and no cats.
But here's the thing. Cat deletes are for anti-social jerks.
60 years ago, this is how bad LA's smog was:
This woman, by the way, is wiping away tears because the smog is making her eyes water.
In 1975, the US government began requiring catalytic converters on all passenger cars in the US. Smog conditions in the United States rapidly improved and there was a huge reduction in airborne carcinogens and acid rain.
The fact of the matter is that gearheads ought to be mindful of environmental stewardship, because we are under suspicion of indifference, and the long term health of our hobby depends on the health of the environment. Hunters join Ducks Unlimited to protect duck habitats, and so should we balance our enthusiasm for the automobile with a sense of civic duty.
The only possible "justification" for cat deletes is that the aggregate environmental impact is small because only a few people do it. But this isn't a justification. It's just selfishness hiding behind other people's willingness to do the right thing, abide by the law, and in doing so benefit the community.
And one more thing. If Mercedes can make a catted, SULEV, twin-turbo vehicle sound like this:
You have no excuse. Buy a well-engineered aftermarket exhaust instead of taking the easy way out and deleting the cats. Do it for your city. Do it for your neighbors. Do it for the future of car culture.