Fuel Pressure Switch replacement

Hello, what exact engine do you have in this? Is this a Natural gas vehicle? There is no 5.6Liter engine listed for this year. Do you mean 4.6 or 5.4L?
It may be easier to look this vehicle up by the VIN number to get the correct information. And also do you mean the Fuel Pressure Sensor? Or the Inertia fuel shut off switch?
The VIN number will be needed to find the correct engine.

Okay, since this is natural gas, I will try to find some information on the conversion kit they use for these. I don't believe there would be much for fuel pressure since it's running on a compressed gas and not really a liquid, but I will see what there is for information.

Okay, so this vehicle is strictly nature gas and not a bi-fuel mix type of fuel system I assume?
And why do you think you have to change a pressure sensor, are you getting a diagnostic trouble code for a fuel pressure sensor and if so, what is the exact code number? This vehicle has different pressure sensors than a regular gasoline engine. It also has different solenoids to control the natural gas tanks opening and closing. It has Fuel Tank Pressure sensors, as well as Fuel tank temperature sensors. So, we need to figure out which sensor you need help with. There's also a different Fuel temperature sensor on the top of the engine to check the gas when it gets to the engine. I did find the correct vehicle with the Vin number though. The I's are actually 1's though.

If you had a problem with any sensor, especially any of the Fuel pressure sensors, the check engine light would be on and there would be a diagnostic trouble code stored in the engine computer (ECM). But I thought you said this is a Natural Gas vehicle? Natural Gas is compressed gas stored in a pressurized tank in the back of the truck, like a propane tank type of setup. Are you just misunderstanding what I was asking? Do you just put regular gasoline in this truck? Is this check engine light on or has it come on and then gone off? And if you had an issue with getting the gas cap off, its not heat that causes that, its probably too much vacuum in the gas tank. But I need to know what kind of Fuel this truck actually takes. Regular 87 octane gasoline?
Fords engine computers run self tests on the fuel system, it runs a vacuum decay test first then if it fails 2 different vacuum tests, it will move on to running a vapor generation test. Its a very complex set of tests it runs. After we figured out what gas this runs on, I think you should take the truck to your local auto parts store and they will scan the engine computer for diagnostic trouble codes for free. Ive been looking at the wrong diagrams because I thought this was a compressed natural gas vehicle which it sounds like it is not.

It's okay, no worries. there's so a few different types of fuel vehicles run off of. so, i just wanted to be sure we were addressing the correct system. Did you have any trouble filling the gas tank? such as the at the gas filler station, did it keep clicking off on you or anything like that? I'm trying to figure out if the gas cap was just on too tight, or if it was excessive vacuum pulling on the gas cap preventing it from coming off. If it was actually that much vacuum in the gas tank then there's a couple possibilities.

There is a valve called the "canister vent valve". This valve opens and closes during different operations of the truck. It is normally open when you turn the truck off. This allows for gas to enter the gas tank and the vapor to escape out of the vent valve and allow room for the new gasoline. If the vent valve fails and stays closed, (they fail all the time FYI) it will be hard to fill the gas tank. The engine computer also closes this vent valve during its self-test of the Evap System. It will close the vent valve and allow engine vacuum to pull on the gas tank, therefore putting the gas tank into a vacuum and a Fuel Tank Pressure sensors watches this vacuum to determine if there is a vapor leak in the entire Fueling system. The Evap system uses another valve called the Purge Valve to pull the vapor into the engine. So, 2 valves at the ends of the fuel system.

So, that's how this system works, sorry for the long description. What I think is happening is the gas cap is supposed to release some of the built-up vacuum especially if the tank was very low it can be hard to get the cap off. So, the Canister Vent valve may not be opening when you turn the truck off, the canister Purge valve may be stuck open, considering how old the truck is, things like this are going to start to fail.

If you can make it to the parts store and have them scan the truck for codes, that might give us some direction. Here is a guide on the Evap system, but I don't think you have a leak, I believe there's an issue with one of these 2 valves. You shut the truck off while getting gas too I hope.

https://www.2carpros.com/articles/evap-system-code-repair

Another possibility is while the gas cap was off, liquid gasoline ended up in the vapor system and is causing either a blockage or is drawing liquid gas threw the vapor system into the vapor canister, then flooding the engine out. This seems to be more of a logical answer because you replaced the gas cap and now still have an issue. These systems can be hard to diagnose. But having someone check to see if the vapor canister (Charcoal Canister) is full of liquid gasoline may be in order. Or you can unplug the Purge valves electrical connector and see if the truck runs better just don't leave it unplugged for long. If you want to try unplugging the Purge valve let me know and I'll try to find a picture of it with the wiring colors to it. It's a 2-wire plug.

The 1st picture is the general location of the purge valve. The 2nd is the wiring colors of the connector on the purge valve, and the 3rd is the valve itself from a 2001 ford that I happened to have. You'll notice the little green cap. If you unplug the electrical connector and the truck runs better, then you know where the fault is.

In the 3rd picture above, the Purge valve picture, if you follow the hose on it going to the Intake manifold (where it draws in the vapor) you can pull that hose off the intake manifold and plug both ends, The purge valve hose and the intake manifold hole where the hose attaches too, And start the engine and let it run for a minute and see if its better, but make sure you plug both of the open hoses, you don't want fuel vapors floating around the engine compartment while the engine is running. This will help rule out if the Purge Valve is stuck open.
Also inspect the Gas Tank filler tube, (where you put on the gas cap) for damage. If you had to really fight to get it off, it might be damaged as well.
Just be careful when working around gas fumes, don't make any sparks.