Hesitation or quick loss of RPM's issue...HELP!

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I have had some weird issues with this truck and im getting close to calling it quits just seems like one thing after another...

I have had the computer/IDM and a few other things replaced in the last 4-6 months with less than 2000 miles on it total. Each time it seems its fine for a little bit. Now the new issue is im going down the road and it will loose RPM almost as if i let up on the gas real quick and then re apply real quick, no dash lights. It started a few weeks ago it would happen maybe once or twice and thats it and then would come back for a day or so or times it would happen a couple times same day. It has been parked for the last two weeks and tonight I take it out to do a few things i've been driving for 20 miles or so no problems, then it comes back does it multiple times luckily im close to home but it happened id say 6-8 times in 5-10mins, which is more then it has ever done and still no dash lights.

Any idea what I should be looking at sensors? would the TPS going bad cause this? any help would be appreciated....

Update - Im going to pull the tuner just to see if it changes anything, I dont think its the problem but its free to try and I dont have $$ to throw at it right now.

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Anyone???? could use a little help...