what does Black and Grey smoke mean?

[TwoStrokes]

I have a 2004 1/2 6.0 F-350 Powerstroke. Over the last couple of days it has gone from a miss fire rough idle and blowing a constant stream of black smoke while driving to rough idle, and blowing a mixture of black and grey smoke while sitting idleing and making a clacking noise, all in a couple of days.
I drove it into town yesterday and i was doing about 60m/h till i got to town and when i stoped at a stop sign and pulled away from it it started making the clacking noise and smoking really bad. It goes away at around 1500 rpm and then the truck just blows black smoke.
I hooked it up to my programer and it tells me i have an unbalanced cylinder # 7 with the error code P0281.
I thought it might just be the ijector, but now that it is blowing dark grey smoke i am wondering if it is more then that?
I started it up this morning and it didn't blow any smoke for about two mins then it just started to blow out that dark grey smoke, but the clacking was gone.
If i unplug injector 7 will it stop getting fuel and can i drive it 400 miles back home?
Any suggestions would be appreciated thanks

[TwoStrokes]

I went ahead and unplugged injector 7 from the wiring harness. the truck still smokes a little but not nearley as bad. Is this going to do any damage to the motor or cylinder?
Can I get away with this for 700km?
Any suggestions would be apreciated
Thanks, Matt

[PROMMO]

might need new factory reflash