firefighter4511

OK so i have a 96 jeep cherokee country. I have been having some issues with it sense i bought it and still haven't figured it out. My jeep will start right up fine every time seems to be fine when its cold but after driving it for about 20-45 min, or its warm. It will start freaking out. Im talking not shifting right, sputtering and backfiring when i go to accelerate fast. Sometimes it will not shift into overdrive and even will stick in just third gear on some occasions. (i'm guessing thats a limp mode to save the trans). All of this occurring once jeep is warm.... I have replaced : fuel filter, tps, cps, wires. cap. rotor. everything i can think of with my jeep experience. Iv had it taken in for diagnoses. No help at ALLLL. can someone please point me in the right direction.