Troubleshooting a P0307 code

[hblock72]

I have a 2007 new body style silverado w/ the 5.3 engine that stated missing on the way home from work the other day. Check engine light came on with a P0307 cylinder #7 misfire code. In successive order, I've done the following clearing the code between each step: 1) swapped #5 and #7 spark plug 2) swapped #5 and #7 plug wire and 3) swapped #5 and #7 coil. After each swap the same P0307 code came back. I assumed I'd find the bad part and a P0305 would come up, but no such luck. So i'm about out of options. Does anybody have any ideas? The plug seemed to have a good bit of fuel on it when I pulled it, so i'm doubtful it's the injector, but who knows. Wondering if it's something mechanical in that cylinder. Again, anyone have any ideas? Thanks.

[Jimmiee]

I'll bet it's the injector. A small piece of debris in there is all it takes.

[hblock72]

Finally gave up and took it to the dealership. They found it had a bad lifter. The good news is it's covered under the 100k powertrain warranty. The bad news is it's got a bad lifter. Oh well, life goes on.