Here is the part where the lawyers speak up …
Notice
Federal and many state laws prohibit the removal, modification or rendering inoperative of any part or element of design affecting emissions of safety on motor vehicles used for transporting persons or property on a street or highway. Violation may result in a fine of up to $27,500 per vehicle. Mechanical and/or electronic performance parts cannot be use used on vehicles used on the streets or highways. These parts may be used only on vehicles used solely in sanctioned off-highway events. No other applications are intended or implied.