'95 3000GT, CEL code 44

So my car started messing up a few weeks ago, with the occasional working-fine-for-a-day issue. My buddy came over and advised me to check the spark plugs and O2 sensors, but the code, 44, is for coil pack and the power transistor unit. Anybody know a good way to narrow it down?

If you can find some used parts, great! If not, change the cheapest parts first…There will be a troubleshooting flow-chart in the factory service manual that would be helpful in isolating the problem…