Okay i have had enough with my truck lately. its a 1999 f150 Lariat with 5.4L and ever since i got the truck a few years ago when it got really cold out it would start hard and not want to stay running. Had to get a new motor last year and still the same thing when it gets really cold it will turn over and fire but won't stay running unless i sit in it while it warms up and hold the RPM's at about 1500 to 2000. The only code that comes up is an evap code that is for the purge valve at the canister by the gas tank. would that cause the issue that im having, i wouldn't think so but im just at a loss with what could be wrong. any help will be appreciated. sorry if this is kinda jumbled around not good at typing what my problems are better talking lol.