I have a 2000 grand cherokee laredo 4l straight 6, recently was passed down to me by my father after he drove it for roughly 18 years. It has just over 255k and up until recently has always ran and drove reliably. A week ago I was driving on the interstate going 70-80 mph and all of a sudden for no noticeable reason it felt as if I had lost power, after letting up on the throttle and coasting for a few seconds while checking my gauges to ensure it wasn't overheating and that I still had oil pressure (which I did, temp around 210 and oil pressure right around 40) I gave it some gas and my rpms made it barley to 1.5k-2k caused a distinguishable "clunk" which I immediately pulled to the shoulder and put it into neutral thinking the engine had blown. After coasting for a few sec and was slowed to about 20-25 put it in 2nd to see if it was something with the transmission which resulted in a similar less than 2000rmp before sputtering and feeling like I'd lost power and idled very rough. I parked immediately and for a second watched the rpms as it roughly idled around 350-400 then almost stalled before recovering back up to 600-750 roughly before I turned off the engine. After sitting for a moment, I started the engine and it fired up instantly like always, attempted to Rev the engine to see if stopping and restarting "reset" whatever it was and before rpms reached 250-300 lost all throttle power and rpms again dropped drastically almost to stalling but recovered after letting off throttle. After calling my dad he suggested that one of the control modules initiated its "limp mode" for some reason and to do a hard reset by disconnect the battery entirely for about 30 seconds which after doing so and starting the engine I was able to drive the few miles left to my destination and didn't have any irregular performance for a few days but again at highway speeds i lost throttle power and car went to "limp mode", after resets it ran fine at city speeds until today where I experienced it and hard resets weren't doing the trick for more than about 500 yards. I just replaced the fuel filter thinking it could be starving due to clogged filter but after driving a few miles it's still happening... anyone experienced the same issue and know how to fix it?