First I would check the end away from the injector. Mine ran into 4 plugs mounted on the firewall behind the battery. Yours may be different, but I had to really clean the plugs due to oxidation.
If all of that looks good, I would clear the code and then I ( and let me stress I) would cut the wires going to the #2 and another one and swap them. If the code changes, you know you have a bad connector at the injector.
I'm not an electrician so maybe someone with more knowledge can provide better guidance.
Sorry I don't have a better pic but this shows two of the plugs that go to the connectors on the firewall.