Hello,

1997..FordF150 4.6L 4x4 Manual transmission ~~

To start ... truck seem to be having misfire issues one day...first thought was gas tank was low and running out of gas with no warning from low fuel light. Made it to station got gas no more trouble. Week or so later climbed in truck that morning went to start it and felt like it was running off 4 cylinders, shaking, misfire and engine light flickering constantly.. eventually died left it off took the Harley to work...

Later that evening after I got home put scanner on it got a code PO453 "Evaporation Emissions Control System Pressure Sensor High Input".. Looked it up.. found the location to be on top fuel tank...first thought great gotta drop tank to replace sensor... after the scan reset sensor.
Next mourning started truck ran great ..no engine light... took it for a spin no problems parked it. Next mourning going to work started it same problem...Shake Rattle and Roll....&#&@^%# !
Friend told me to unhook ground cable to reset computer... did it..left it for couple hours..hooked it back up..started fine..no engine light running great drove it 3 to 4 miles no problems. Took it to car wash cleaned it started again drove home parked it. Next mourning same thing shaky shaky...
Took to local shop to have it checked out (drove it there ran great with engine light on)... they seem to think sensor is OK.... Their thought P C M..
Supposedly took PCM off cleaned contacts and one of the mechanics drove truck home with no problems...next mourning same issue shaky shaky....
Wanna know any thoughts on the matter... would appreciate it..
New PCM right direction ?

 

New PCM.. No.
You have to get a lead on it or you will spend a lot of money guessing.
Get a scanner on it, set up to trap the problem when it happens so you have some idea what's going on.
Good luck