can we clean are owen turbos if they have drilled and tapped ?

 

I'm not even sure how to go about doing it. Should be under warranty??

 

why I ask is Im about to do the deletes and the more I can do my self the better

 

You can clean your own, if you know what you're doing. I suggest making good friends with one of the dealer techs, and get him to show you how to do it properly. There is a special tool/adapter you need to hook up to the cans.
If it were me, I would have them get it good and clean right before you do your deletes...after which, the buildup shouldn't be an issue.