Earlier quoted context omitted.
it is illegal to tamper with any part of the emissions control system on your car. Can you cite the law? I know the EPA has civilly pursues companies that make products that bypass emission controls. But haven’t seen or heard anything that goes as fat as you suggest. E.g.: https://www.dinancars.com/products/software-tuning/engine-tu... This allows you to change the engine programming on a BMW. They do note it is not…
"It is a crime to knowingly falsify, tamper with, render inaccurate, or fail to install any "monitoring device or method" required under the Clean Air Act, including a vehicle’s on-board diagnostic system. Clean Air Act section 113(c)(2)(C)." https://www.epa.gov/sites/default/files/2020-12/documents/ta...
Tampering. You may not remove or render inoperative any device or element of design installed on or in engines/equipment in compliance with the regulations prior to its sale and delivery to the ultimate purchaser.
https://www.ecfr.gov/current/title-40/part-1068/section-1068...
It seems primarily about bypassing or disabling emission controls, not user controlled fuel mapping, or mods like putting in a performance air filter or exhaust. But EPA does consider a flex fuel conversion tampering.
https://afdc.energy.gov/bulletins/technology_bulletin_0807.h...