Rough Cold Start / Cylinder 4 Misfire

Hey Everyone,

2003 V6 Pre-runner AT

Issue I'm having is when I start up my truck in the morning the engine starts to stutter but stops after about 15 seconds. Only happens after the truck has been sitting for a while. Check engine light is a cylinder 4 misfire.

Troubleshooting so far:
Replaced all plugs/wires
Moved coil to different cylinder, no change in code
Replaced cylinder 4 fuel injector

Out of ideas at this point, has anyone else experienced this and found a fix that I haven't already tried?

 

FIXED

Figured I'd post what the problem was for anyone else that's searching the forum for the same issue.
Had a leaking head gasket that was leaking coolant into my 4th cylinder. Rather than replacing the head gaskets my mechanic used an engine block sealant that fixed it. Truck is running and starting noticeably better, no more misfires and it only cost $200 with labor. Here's a link if you want to know how to do it yourself, pretty self explanatory http://www.wikihow.com/Fix-a-Head-Gasket-With-Engine-Block-Sealer