yeh these ECU's dont detect missfires unforunately, unless its maybe a really late one with the integrated coils.
The two usual culprits are a coil or the ignition amplifier on the airbox.
Generally, a coil will break down under high load, so it'll drive fine, then missfire when you floor it. Whereas the amplifier will just die, usually on cylinder 2 for some reason.
Occasionally there are exceptions, but for a completely dead cylinder i'd be looking at the ICM first, or for load related i'd do the coils first.