2001 F150 xlt 4.2
219,000
Truck is from Texas with no rust, mostly rebuilt. I found this info. here. What is the mostly likely cause, Is there anything more I should know?
A P0453 code means that a reading from the engine's evaporative pressure sensor is higher than normal, indicating changes in pressure that are out of factory specification.
Faulty Fuel Tank Pressure Sensor · Fuel Tank Pressure Sensor harness is open or shorted · Fuel Tank Pressure Sensor has poor electrical connection · Damaged PCM.

 

There are pinpoint tests for that code
I do not have a 2001 PCED (that is where you will find the pinpoint tests)
Also available free at the library on AllData (or you can subscribe for substantial dough)
The library had the educational version, which is a better platform IMO
A thorough visual inspection is warranted, (the first step) find that sensor connector and verify if it is plugged in
An uncommon problem IMO, you can get 5 of those sensors at the junkyard for 20 bucks

 

I replaced the Fuel Tank Pressure Sensor. also all the the vent hose looked very old so i replaced them too. No more code.