My mother passed away a few months ago. She left no will. She left some bills and an auto loan with a balance. I have been making payments on the car and it is almost paid off. I have not filed for probate, but I do have letters of renunciation filled out by my family members renouncing the right to administer the estate and asking that letters of administration are assigned to me. The car is located, insured & registered in NJ and my mother passed away and lived in PA. My brother is driving it for now since he was also on the insurance. How can I get the car changed into my name after it is paid in full or do I need to go through probate? If I go through probate, will they take her car away to pay for all the bills she had?

Since there is no will you must first go to court and get yourself named as the executor (sometime called personal representative). Then you have the responsibility of paying off her final bills - using your mother's assets (not yours) - and only after that you can think about distributing the remainder of her estate to the heirs, which are most likely you and your siblings in equal share. You should not be paying her car loan! Instead any payments of her bills should come from her assets. Since there is an outstanding car loan you can't change ownership until the loan is paid off or transitioned to another payer (yourself?) - contact the lender, tell them the situation, and see what options you have.

You should not have been paying for her car with your money, you may well lose all the money you have paid to this point.

This will need to be handled though probate most likely.

I'm sticking my neck out here...
My dad wrote down (to me and my sister) that he wanted me to have his car, but he didn't get around to signing it over, and I wouldn't ask him, hoping he'd live past 100.
When I found out what I'd have to do with notaries and probate and inventories and so on, PLUS having to drive to a very far away DMV and stand in much longer lines, I cheated and pretended he was still alive and gifted it to me. (Gift form available on state web sites).
Not suggesting that you do this at all. Even the trustee at the bank knew though.

Joy - I get what you're saying... and far be it from me to criticize for accomplishing exactly what your father desired presumably without cheating anyone out of what was due them. But in the OP's case there is an outstanding loan that must be paid off before the OP can get hold of the title. It also seems there are debts outstanding and creditors have a right to expect to get paid out of the remaining assets of the estate.

Oops, right, thanks...