Sales Agreements: Used Car Has No Catalytic Converter

I bought a car from a NJ used car Dealership about a month ago, the car was originally inspected in NY but the inspection was expired. The day after I bought the car the check engine light came on, called the dealer brought it to them and they just clear the code, then a couple of days later same thing again.

When I received the registration and plates I took the car to a NJMVC inspection facility and the car failed for 3 reasons: 2 codes and as per the inspector the car has no catalytic converter. The gentleman very politely explained to me what it has to be done and told me to reach out to the dealership due that it is illegal so sell a car in NJ without catalytic converter.

I brought the car to the dealer along with the paper work provided and the car dealer's manager said: "We will take care of this, we will get the necessary parts to get your car the in compliance" I left the car for the repairs and when I got back to get it I found an inspection sticker attached to the windshield, no engine light on, so, apparently everything was ok.

I tried to start the car and it won't, after a couple of tries it turned on, tried to drive it and stalled in the middle of the road so I had to push it back to the dealer. The mechanic said it was the fuel pump that failed; allegedly they replace the pump and I took the car back home after almost a week at the dealer facility. Once again the check engine light is on, the vehicle still without catalytic and an Inspection Sticker is on the windshield good until 3/2020. What else can I do?

Sales Agreements: Used Car Has No Catalytic Converter