Why does my fuel ignition coil keep going bad

What is your question?

I engine light flashing indicating two cyclinders are not firing. Raw fuel being pushed through caddilidic converter. Destroying the converter. Had converter replaced along with fuel ignition coil. Week later after driving for 10 hours delivering pizza. Car engine light flashing again. Car won't run when giving it gas. Fuel ignition coil replaced again. Mechicanics said they other new one was bad. Once another new one put in. After 3 hours driving it engine light flashes again and car won't run right again. What would be causing the fuel ignition coil to keep getting fried??