5.4L Motor. So, recently my cold starts are rough. For about ten to fifteen seconds when truck is cold it idles rough then clears up fine. Sometimes it revs to 1500rmps then goes right down to 800 and idles. Got a 02 sensor code and replaced the 02. Some mornings I notice white smoke coming from the hood when I first start the truck. Appears from driver side. It goes away shortly though Once I saw that I opened the hood and saw some oil traveling down the driver side of the block. Climbed under the truck and saw oil coming from up top and draining down the left side of the transmission and travels back to the transfer case. I have not had the time to clean up the oil and run the truck to see if I can spot the leak. I also sometimes smell fuel badly when I am outside the truck and it is running. Again, this is coming from the left side. I do not smell it on the right side of the truck. There are no trouble codes. I am open to all suggestions.

Thank you.