Hey guys my grandpa has a 99 f150 with the 4.6. His truck has been stalling/sputtering when driving and even having a slightly rough idle. He has replaced the spark plugs and fuel filter and ran HEET throught the fuel system. Then PO316 code started showing up. So we replaced the crankshaft position sensor and reset the computer and code went away and truck started right up and was purring like a new one. So we drove it to town and about 3 miles down the road truck started doing the same thing. It cuts out while driving and sometimes will even cut off. But will start back up. And no code is being thrown now. So im puzzled as to what it could be. Maybe a TPS? My 92 had similar affects from a TPS. Any help would be appreicated it. Dont really have the money to take it into the shop and my grandpa needs his truck!

 

Correction it's a 2002 4.6 not a 99

 

Sound like a basic electrical power issue.
Fuse box supply, fuse seating, PCM relay etc.
With an issue like this, there can be no code set because if power is lost nothing works and the PCM cannot look at it's own basic power supply.
You will have to check this all out because there is nothing solid to go on.
Good luck.