F 150 2003 4.2 losing acceleration and it's intermediate
 

Hello, I have a 2003 f 150 4.2 and it randomly decides to lose acceleration. It's doesn't happen all the time. I have changed my fuel filter and spark plugs with coils, i have also changed my fuel pump, pcv valve, throttle body and tps. I have taken it to NTB and another mechanic. They each said they can't find the problem. I go days without any problems and then randomly it will happen. I'm thinking of just getting rid of it. Does anyone have an idea of what It can be ? Also they said they checked for a vaccum leak.