Same issue except it only happens when cold. Many suggestions that it may be the primary computer. The suggestion it to bag it, encompass the computer which is right side forward facing the vehicle from front on a 99 in a garbage bag and surf a hair dryer in it . Run long enough to heat up the computer and allow it the heat all the way though. If all else is cold and it fixes it then the computer is broke.
If not then the more likely and cheap option is air temp sene pick up on manifold. Hmmmmm. Try tomorrow