I can't say I've ever seen only one bank firing injectors before. Knowing the layout of the transistors that control the injectors inside the computer, I can't even see how a single burnt trace could take out only one bank. I could see it taking out two on each bank though.
Your code 15 can point towards very unpredictable behavior though. 15 can be caused by 2 things. Power or ground interrupt to the PCM, or a corrupt rom (whether stock or aftermarket chip).
Basically, if you have power on pin 1 at all times, your grounds are good, you don't have an aftermarket chip, and you still get code 15, then the rom failed checksum.
The calibration (tune) is stored in the rom chip in the PCM. It's a bunch of zeros and ones at this level. When you turn the key on the computer does a quick self check, it adds up all of those ones and zeros based on a formula of their positions and comes up with a value (checksum). It compares this value to a value stored in the PCM of what the checksum should be. Let's say the stored value is 55555 and on the self check it calculates a value 55556, well, that's wrong so it throws code 15.
That one digit being off means that there is a one or zero that is out of place in the tune. It could be something you'd never realize like commanding 27 degrees of spark advance in a table instead of 28. Or, it could be something huge like the computer thinking it's a 4 cylinder instead of 8. When a PCM fails checksum, you just can't trust it anymore.
An aftermarket chip just replaces the entire rom with a custom one. It's common for aftermarket chips to throw code 15 because often the guy writing the tune doesn't recalculate the checksum and store the new value. This was very common in the early days, but even today depending on the software used by the tuner I still see it from time to time. Removing the chip returns the PCM back to the factory state and 15 usually goes away. I've also written chips with the correct checksum value and had them do just fine in a PCM with a corrupt rom.
