Think of this when you vote in November.
Note how it says Certified motor vehicles and motor vehicle engines and their emission control devices.
That sounds like they want to prevent ANY changes at all to the vehicle from how it was manufactured.
http://www.sema.org/news/2016/02/08/epa-seeks-to-prohibit-conversion-of-vehicles-into-racecarsCertified motor vehicles and motor vehicle engines and their emission control devices must remain in their certified configuration even if they are used solely for competition or if they become nonroad vehicles or engines; anyone modifying a certified motor vehicle or motor vehicle engine for any reason is subject to the tampering and defeat device prohibitions of paragraph (a)(3) of this section and 42 U.S.C. 7522(a)(3).
Note how it says Certified motor vehicles and motor vehicle engines and their emission control devices.
That sounds like they want to prevent ANY changes at all to the vehicle from how it was manufactured.