I have a 2001 Dakota with the 3.9 and when I start the truck up when it's cold after 3 min it will idle rough and have no power if you try to drive it. But after about 3 min it smooths out and runs fine I have no idea what it could be I've done spark plugs, wires, cleaned the tb, and replaced the iac valve and the only code is p0455 evap leak any ideas what it could be?

 

You may have a vacuum leak. Check all your hoses.