Ok,
First job is to determine which bank isnt working. So pull off both 2 and 3, see if it makes a difference? If not, try 1 and 4.

When you have figured which two dont work, you can see which side of the circuit to investigate. The plug on the coil has one live (Middle) and two triggers, one for each bank.

You then possibly have two ignition amps? If so, again, they will be one for each bank.

Finally, ECU drive depends on what your running at the ECU?