The codes read all cylinders were misfiring and the fuel pressure regulator had a problem. I replaced spark plugs, coil packs, and fuel pump regulator. Vehicle still wouldn't start up. Took it to the dealer to check further. They performed a compression test to rule out timing chain issues and determined the rear catalytic converter was completely clogged. The dealer replaced the rear catalytic converter and changed the oil and filter. I paid $1300 for the repair, pulled out of the parking lot and made it 1/4 mile down the road, smoke starts rolling out from under the hood. I drove back to the dealership and they told me the 3rd cylinder is dead and I need a new engine. Before the initial work I had done to the car the engine performed fine. How did the engine blow?