hey guys i have a 00-01 frankencar midpipe, on the bottom of the midpipe there's a one inch hole what do i do with that hole?

 

i assume you are talking about the air temp sensor hole. go to a parts store and look in the help section. they should be in red packages and it is a bunch of misc parts. i found something to plug mine when i had it. if you cannot find something there you could also use electrical tape around it.