Does the check engine light com on when it does that loss of power and bucking? If so, retrieve that code from the computers memory. That should give us a clue as to what is going wrong. If no check engine light, you are pretty much stuck with testing for intermittent problems and that includes mostly loose wiring connections. Now since it appears to be happening when opening the throttle, I would begin by wiggling the wiring connection at the TPS ( throttle position sensor) while the engine is idling, or even in neutral and reving to listen if wiggling makes the rpm change.
Then depending on what other items it has, wiggling the wiring connections at the MAP sensor and/or MAF sensor, some vehicles have one or the other and some even have both.
Let me know if you retrieve a code.
Check engine light is on intermittently due to a power steering pressure switch malfunction so can't track it that way. Tried moving wires and tapping the TPS while brake-torquing it to 2000 rpm. No change. Your name and picture makes me ask the question, are you a Chrysler dealer tech that specific brand experience? What you gave me is good general advice, but these things have some peculiarities. If not please forward this on Thanks, Dan
Sorry to take so long to respond, crazy around here. Finally got it in the air to look at the O2 sensor on the cat. Looks fine, nothing out of the ordinary. Did it bad today (dry) barely pull on highway, then it clears up. Do these things need an O2 sensor as part of a regular maintenance? have had since 33K and 5 years now. Rockauto shows an upstream and downstream?
Thanks for the reply. On fourth tank, first two fill ups had Heet added. Third tank not and ran low as I thought I would have to pull sock in tank as there is no fuel filter(?). Starts to act up about half tank and then stops. Goes days where it doesn't act up. Have been having check engine light on intermittently from a PS sensor that we have been living with. Last 45 days or so it has been staying on. Parked in garage as I have to do front control arm rear lower bushings, so can't get it to a parts store to use their scanner