[TWG1]

Unburned fuel would explain torched cats. Could also be difficult to reproduce when cold. Had a similar issue on my F150. Port injector was sticking, sending unburnt fuel to exhaust. It was igniting when it hit hot cat and destroyed it. My codes were single bank misfires and faulty cat. A bad coil could absolutely be root cause, and could be aggravated when engine bay (and coil) temps rise, increasing electrical resistance.