Legal Question in Business Law in Georgia

You might be sued.

As is means that there is no warranty by him that the vehicle is in good condition, so if it is not, that is your problem rather than being his. If you stop paying, he has the right to enforce the contract. The only recourse he has would be if you could prove that he knew about the engine problem before the sale, which could amount to fraud. However, this would be your burden to prove. The best bet, since this is a friend, is to see if you can work out a way to offset the amount you owe him by the amount it will take to fix the vehicle, or see if he will meet you half way.