Since the child is in Foster Care, I'm pretty sure his foster parents will deliver him for the DNA test.

Since a judge has not signed a support order based on the mother's failure to comply to a court order, ask child support to compel the mother to a DNA and see where that goes, which is probably nowhere. Also ask child support for a copy of the support order signed by a judge. Child support enforcment can only enforce a legitimate court order and so far you stated no order exists. A DNA test with two people is well under the accpeted 99% probability to prove conclusively your are the father. He may have some of your markers but without mom's the best you might get is 75% and that doeesn't legally fly. I wouldn't get an attorney until you get some paperwork from support enforcement

I can see where you would want a DNA test to find out if the child is yours if there is any dalt, however you need to know this there is a statue of limitation on how long you can go back and ask for a DNA test, inorder to not have to pay child support, and the child is 17 now and even if you were to get the parenty test taken it would finally tell you what you need to know and that is if he is your child, but there is no way that your going to get that back child support wiped off even if it does turn out the child is not yours, infact you would still have to continue to pay until the child reaches the age of 18 or graduates high school. You can contact a lawyer for additional information but you have to pay all your back erarages, the only one that could wipe those back child support paymesnt off is the mother if you could get her to contact the child support services and tell them your'e paid her in full, but if she has ever recieved any state benefits (Welfare) then the mother cannot do this at all.