It could be the sensor. My previous F150 had a low oil pressure indication that would come on only when the outside temperature was below about 30 F. Replacing the sensor fixed it.

 

Follow the line from the canister to the tank. For a problem that directly correlates with temperature, I doubt it's a kink in the line or bad canister. That would show up all the time.

 

it started as a only when its cold issue but its now on all the time. I even tried clearing it after I replaced the last part and it came back within a few days

 

Did you change the FTP (Fuel Tank Pressure) sensor when you say "replaced the last part"? What exactly have you changed out? I'm currently fighting an issue on my daughter's F150 that I believe is either a sensor or wiring issue. The FTP is mounted on the fuel tank and part of a plastic tube that attaches to the vapor blocking valve. You can monitor FTP output using FORScan or a diagnostic scan tool. My daughter's truck shows 4.2 kPa even though the fuel tank is open (using the auxiliary funnel).

 

I have changed the purge flow solenoid as well as the vent solenoid

 

stupid question but does anyone know the location of the Fuel Injector Pressure Sensor? I figured I would give it a shot

 

Ill be damned if I can find the thing

 

I'll bet you $100 that within 10 minutes I could run searches on The Google and Youtube and find specific instructions for that sensor on your truck. Deal?

 

Well considering I have tried that first.and it's only the wrong sensor or car.good luck

 

Already found it and watched a couple videos for my engine. We don't know which engine you have because you didn't tell us, but be sure you're including the engine and year in your search. FYI, most of the sensors I've found even on different engines and years look very similar, and are mounted pretty much exactly where I would expect it to be. Takes less than 5 minutes to change. Good luck.