Cats are ineffective until they heat up too. My drive to work is 2 minutes long. My factory cats haven't done sh!t for the environment for 75% of all the miles on the car.
You get headers, and you've moved them even further down the exhaust stream. They say 5 minutes on a typical car before the cat is at operating temp. It would be even longer with headers + HF cats.
I'm not worried about the EPA prosecuting me for something that is perfectly legal in my state.
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