2002 ram 3.7 no power in 5th gear

All that follows is assumin' you have a manual tranny, if you have an auto, you may be havin' problems with downshifting or lockup...so it all depends. BUT, either way...First, try a tank of premuim gas n see what happens...second, if you have access to a simple computer scanner that can display live data (round $30-$50/Walmart or Amazon)...check for any codes n forget anything subsequent...if not...check your fuel trims whilst driving, pay close attention to the trims when the problem occurs. If fuel trims high (above 10) for extended periods of time, maybe fuel pump, faulty injector (this'll set a CEL light/probly), dirty air filter or vacuum leak. If fuel trims negative (below -10) for extended periods of time possible faulty injector, bad plug wire/fowled plug (will cause rough idle usually) clogged/clogging cat. Should getcha started...no pun intended.