can computor give false readings

I have replaced alot of partson this van and ikeep getting a code po101 i have replaced the m a f sensor,M A P SENSOR, DIST, WIRES PLUGS, TPS SWITCH,FUEL PUMP,FILTER i STILL HAVE A PROBLEM WITH IT LOSING POWER, ENGINE STUBLES,WHEN THIS HAPPENS IF YOU KEEP YOUR FOOT ON THE GAS PEDAL IT WILL PICK BACK UP AND RUN. ALSO STUMBLES BETWEEN SHIFTS