Purchased Unsafe Car from Used Car Lot

Before I bought the car the engine light was on, he said it was just probably bad gas and he turned it off. It came back on and I learned it was a bad catalytic converter which isn't cheap. He sold the car to me after stating he drove it for hundreds of miles without a problem, when I went to his mechanic for inspection they showed me a tire that was so worn down there were threads coming out of the tire, it could blow at any minute. They barely let me drive away. They also gave me a list of about 10 things that it needed. Just to pass inspection it needed four tires, two break pads, two rotors, and two inner tie rods. The dealer refused to give me money towards new tires, but game me two used tires from a junk yard that I couldn't use because they were asymmetrical, and it's a four wheel drive vehicle. He's would only pay the other stuff for inspection. I had to spend over 300 on tires after smelling burning rubber on the way to Walmart. I asked him politely if I could return it, he said no since I had it for a couple days, then he threatened not to pay for the inspection after I questioned his character. I have recordings of him say some of this stuff and I have pictures of the tire. I signed an as is paper, but on the same paper there is a dealer warranty section and under systems covered he wrote " not inspectable, not road Worthy, needs work." Legally speaking what are my options. If you need more information, please ask.

Purchased Unsafe Car from Used Car Lot