My son's 06 Ford F150 4X4 is stalling out when he accelerates. As long as the truck is in drive or neutral the truck idles fine. When he pushes the gas it begins to stall when he gets to about 20mph. We had it put on a computer and it had misfires for cylinder 1, 5, and 6. We replaced those along with the coil packs and it still stalls when you accelerate. Does anybody have an idea as to what the problem could be?

 

Did you replace ALL the spark plugs? You should have done that and tested it before buying any coils. How many miles are on the truck? How many miles on the fuel filter? It should be changed every 30k miles.