Of course, if you're replacing a bad wire, it may not matter, but if any one of the old wires is still good, it's best to keep it as a spare.Grasp the plug wire by the boot at the plug end.

One of the tell-tale signs of a bad ignition coil or bad spark plug is a fluttery or inconsistent idle. ... Attach the ground wire. Plug in the coil connector.

Diagnosing a clogged injector is not always easy because the symptoms act similar to low compression or an ignition problem, such as a bad ignition coil, a broken spark plug wire, a bad spark plug ...

The next day I go out and buy spark plugs, spark plug wires, a ratchet, and a spark plug socket (but not before buying the wrong size socket twice) and swapped out the bad plugs/wires.