I just found out that I have a 16 yr old son and met him and we had a dna test done and it showed I was the father but he does not like rules and we don't get along I have since cut ties with him as all he wants is money so if his mother takes me to court will I have to pay back child support

ANY question on law needs to include your general locale as laws vary by area.

There is certainly a possibility that you might have to pay back support. A support order may have been issued long ago, but never applied to you since you may not have been easily found. If the mother ever received public assistance the state will want to be reimbursed.

Even if there was never a filing, some states do allow retroactive awards.

So, I would do nothing until the mother does file, then get an attorney.