2004 Ford Ranger running problems in freezing temperatures

I have 2004 Ford ranger 3.0L v6. It started running bad at first when it was cold. It has gotten worse over the last few months. It can be parked and idling or it can do it while driving or stopped at a light. If parked while idling or stopped at a light the engine will act and sound like it is bogged down and the rpm's drop to about 500 and it is idling so rough that the entire truck is shaking. When it act's up while driving it will bog down like I am trying to pull a tree that is still in the ground. I can either shut the truck off for a few sec. Then start it back up and it will run for about 5-10 min then mess up again. I can also continue to drive it while it is bogged down and after about 30-60 sec. It will break free as if someone cut the line I was trying to pull the tree with. 5-10 min later it starts over. It only does these things when the temperature outside is either close or below freezing. The colder it is the worst it does. I have replaced the coil, plugs, wires, idle control valve, and the mass air flow sensor. When I replaced the sensor there was an arch spot on the metal side of it. Dont know if that will help or not. Also when the truck goes to acting up the engine light comes on and the codes it throws say that numbers 1, 2, 3 cylinders are misfiring. I think that is just a side effect of whatever is happening because the light comes on about 30 sec after the truck goes to messing up. I have taken it to a ford dealership 3 times and they are lost. They cannot figure out what it is and just keep telling me to bring it back in and maybe one day they can tell me something. I appreciate anything you tell me to help with my problem.