I need help finding out why my jeep is going dead?

starts up fine and does fine throttleing up in park but when u pull in gear trys to go dead when you give it gas and put in reverse it skips bad and its got new plugs/wires/distribitor/control moduel/o2 sensor/temp sensor/and new tps whats left ? computer. and a new cap and rotor. any help would be great or any suggestions.