I have a 2003 Ram 2500 Diesel automatic with 90,000 original miles that began cutting out 6 months ago. Very noticeable at low RPMs when accelerating. Will also cut out when in neutral when accelerator is pressed. When it cuts out, RPMs drop rapidly for a second then picks back up. It will cycle like this while accelerating until at cruising speed. When at cruising speed, if accelerator is pressed, it will cut out then as well.

NO codes or check engine lights.

Between my mechanic and myself the following have been done:
~Replaced fuel filter
~Replaced fuel pump on back side of filter housing
~Replaced CP3 fuel pump
~Replaced MAF sensor
~Replaced TPS
~Replaced worn out rubber hose on high pressure side of turbo that comes off of turbo

My mechanic is out of ideas.

I had read on a forum that the wiring harness between the TPS sensor and the computer can go bad. I ordered a harness to bypass the stock harness, but the connector was different than stock so it doesnt work.

Any ideas?