when are you going to replace the intake gaskets?

other than the issue going away when warm and reading your description

intake gaskets are my best guess for you

 

Sorry if I am bringing up a fixed issue.

I ran into an issue like this. Thought it was 02 sensor first, then possibly a fuel issue/clogged filter/bad fuel pump/ignition coil... I felt like I was chasing gremlins!

Turns out that my engine coolant temp sensor connector had cracked. It was allowing one of the wires to break contact and it made the truck stumble and hesitate. I was chasing ghosts! Never got a SES light except for misfires. I even changed the O2's twice thinking I might have bought the wrong part #.

Worth looking at your connector to make sure it is intact. Front of the drivers side head. Cost me all of $13 shipped to my door, and never had another problem since.

If this doesn't fix your issue, maybe it will help someone else down the road.