2008 Ram SLT 5.7 L Hemi 138,000 Miles

Drove a couple days ago no problems. Started it today and running very rough with Check Engine Light on. Scanner says Code P0207, which is for fuel injector circuit.

Is testing/replacing the injector the 1st step or is there something else to check first?
Of course #7 is the toughest one to get to.

Thanks in advance for thoughts. Any suggestions/instructions appreciated.

Edit: Found the problem. A rodent chewed through the wires going to the injector, leaving only nubs where it comes out of the harness. Was able to get the tape unwrapped enough to be able to get about 1" of leeway on the wires so tomorrow will try to solder and heat shrink and keep fingers crossed.

Also blew down his little house he'd started to build with compressed air, soaked a paper towel with peppermint oil and rubbed all the exposed wires I could find with it, and set a mousetrap under the hood.

Edit 2: Was able to successfully fix the wires using two of those small heat shrink tubes that have the solder built into the middle of them. Runs fine now, cleared codes.