Earlier this evening, I replaced (another) fuel injector in my 09 Journey SXT (3.5L V6). I got everything buttoned back up and when I took it for a test drive, I got a different code! P0305 (cylinder 5 misfire).

I know that one of the symptoms of a misfire is that the engine will run rough, since one of the cylinders isn't firing properly. At idle, the engine shows this symptom.

Here's where it gets weird.

Off idle, when the throttle is opened up (accelerating and cruising), the engine is just fine. Smooth as silk! But, once it gets back down to idle (at a stop light or parking it, for example), it runs rough again.

Any thoughts for what I can/should do to fix this? It was late when I tested this and the auto parts places were all closed, so I couldn't go get a new set of plugs (my go-to fix for misfires), so that's on my list, but has anyone else had something like this happen to their vehicle before?

Thanks in advance for any and all comments about this.