That article doesn't have any content, and I didn't feel like chasing all the links to find something substantive.
From what I have read elsewhere: technically, they are not targeting "racing." But they are targeting formerly street-legal vehicles, that are modified for racing . . . . which is probably 95% of the cars that are used for racing. They are saying that once a car is certified to be EPA compliant, it can never be modified in a way that makes it non-EPA compliant, even if it is going to be used off road, as in for racing.
They also seek to make parts that can be used to modify an EPA compliant car to be non-compliant illegal.
So . . . .
Off road X-pipe? Illegal. Manufacturers out of business.
High flow catted x-pipe? Illegal.
Long tube headers? Illegal.
Cold air intake? Not sure, probably illegal.
Change rear gears from 3.31 to 3.73? Not sure, does that affect emissions? Yeah, kinda . . . illegal.
Exactly. If you change anything on the car that requires a tune, you are modifying the emissions and instantly you are breaking the law. Which means that any manufacturer that creates tunes, has to have EVERY SINGLE tune certified with EPA testing or it is illegal. It doesn't matter if the tune passes emissions or not. Even if it has great emissions, it still has to pass the EPA testing and be certified.
That means BAMA/LUND/etc would have to emissions test every single tune they make. No aftermarket company is going to have the capabilities or money to due that, and even if they did they would have to certify YOUR car at the EPA testing facility because it is not exactly like any other mustang they have already certified.
I guess the EPA just wants us to put stickers and wings on our cars because that is about the only thing you will be able to legally do to your car if this law comes into effect. Hell, wings add drag which reduces emissions, that might even be illegal.
The biggest issue I have here is that the number of people that modify there cars are probably less than 1% of the cars on the road. This entire law is just the EPA being bored. They need to go find something else to regulate that actually has an impact, because targeting the automotive enthusiast community is going to have zero impact on the environment.