text: is there a federal law that prohibits states from requiring factory parts for auto repairs? i think i remember hearing about a federal regulation that prohibits individual states from requiring the use of original (oe) parts for automotive repairs. can anybody point me in the right direction as to where i can find this? thanks. i haven't been able to find anything like that by searching the us code, and it doesn't sound like something that is even within congress' powers. that is clearly something that each state should be able to decide for itself. they would have to make an extremely hard case for it being an interstate commerce issue, and without that, it's definitely unconstitutional.