Check the harness coming off of the coils, then check the harness coming off of the ecm. I don't have an '03 9r manual around, but I am sure you can trace which wires are ground/hot lead on the coil circuit. From there, it is a matter of painstakingly checking the wires for cracks, cuts, gouges. The best way is to use a multimeter probe and probe every foot or so. When you see a drop below the ~12V (I think), then you trace it back to where you may find an opening in the insolation. That's your short. I had similar codes on my rear fuel injector, but was tipped off about a manufacturing flaw in the harness that lead to this problem. Aside from that, it could just be age or general wear and tear. Good luck!