Has anyone had this problem before?

you need to check the free play in the timing chain and gears in it, when they get so much play in them the computer can no longer time the engine right and will cause a bad loss of power on it,those need to be replaced at about 150 thousand in any dodge engine built that runs a chain and gears if you don't you will loose enormous amounts of power,it don't matter what you do to the top of the engine if its not timing its self right it will continue to loose power,id check the free play and also run a fuel pressure test on it,mine broke a few weeks ago at 140 thousand,so your lucky it hasn't broke in too yet,the timing is where you get your power from on any engine,if its out of time it don't matter what you do to it ,it still wont run right until this is corrected,good luck,and have good holiday season,