I have heard, and who knows how credible it is, but an apprentice could get away with it if it were a forced induction car, but if its N/A then you probably shouldnt port it yourself. Like I said, who knows how true it is. I wouldnt bother though man, how would you be 110% sure you got all the metal shavings? You would almost have to have a pro do one of those hot wash things, I dont know what they are called but it cleans them perfectly, and you dont have anything like that at home...