Is the truck a 100 series? 4.2 fte engine code have a common problem with the wiring to the fuel pump valve solinoid, it has other names but the wiring loom is too tight and at around 200k ish the pins pull out the plug and cause your fault, I had it on mine, I guy on YouTube has taken his engine out when I’m pretty sure he had this issues, if you Google it it’s quite well documented fault in 100 series with fte engines.