2005 Explorer Eddie Bauer 4.6L v8 Repeating DTC Error Code P0463

[Boeing757rb211]

So i have a 2005 Explorer Eddie Bauer Edition with the 4.6L v8 which i really LOVE like my own child in ALMOST perfect condition, Inside and Out especially considering its Just hit 250,000 Miles. A few months ago, i noticed just after i filled up the gas tank all the way full ( Like when the gas pump stops itself ) Full,,, That the Gas gauge in the cluster would remain where it previously was upon startup, it would than maybe go up a little sometimes not, but would than always drop down to Below Empty, further Below than when the ignition is off and all the Gauges are at their stop points. VERY soon right afterwards it would trip the Check Engine light. So i pulled the codes and got DTC P0463 and P0456 codes. ( I would than Erase the codes so the Check Engine light would go off, although the Gas Needle would stay Below its normal Empty Resting point for about 25 to 50 Miles of driving, after which the Gas Needle as well as the trucks "Miles to Empty Display" would just start going up to its accurate level, and this was happening ONLY when filled up with gas to Full but every single time i filled up ). I did some research all over the internet on this specific problem alot throughout these forums,, and one major recurring theme was the Fuel Level Sending Unit ( Which is apparently part of the Fuel Pump and Inside of the Fuel Tank itself ) over time eventually gets coated with dirt and debris and eventually Sulfur deposits from 10's of 1,000's of Miles could coat and cover the Fuel Level Sensor to the point of causing this problem. So after much research, i bought the recommended Chevron Techron Concentrate Plus Fuel System Cleaner: Which to its benefit Actually states in their product description..... " Cleans, restores, and protects the entire fuel system, including SULFUR-contaminated fuel gauge sensors." Seemed to be the perfect information leading to the perfect product to fix the problem, so i went for it and used the products exact instructions on amount to use and how to use it. Surprisingly the Fuel System Cleaner did seem to help alot both with this specific problem and just a slight gain in power and engine idling smoothness so it definitely cleaned/cleared something or somethings off the Fuel System of the truck. Problem is and which i am still having is it never completely fixed the Fuel Level Sensor issue. Although i believe it did help somewhat,,, the problem is still there, but slightly different. I dont get the P0456 DTC code at all anymore, and i dont have the Gas Gauge going below its normal resting point at Empty when the tank is completely filled up anymore. Now when i fill up the tank completely full,, all i get is the Gas Needle going to its Normal Resting Empty position, and the Check Engine light with ONLY the P0463 DTC Code for about 20-50 Miles,,, After which Both the Gas Needle and the Miles to Empty Display both go back to their normal "Full" Readings and with no further issue with either the Gauge or Miles to Empty Readings until of course i have to fill up again ( Which of course in these Explorers isn't that much time ), And than the same issue just keeps repeating itself every single time i fill up. Very VERY rarely the only thing i notice is that it WON'T "Trip" the Check Engine Light or throw any codes even after its Filled up and the Gas Needle Still goes down to Empty for the first 20-50 Miles of driving. Of course there is the obvious drop the Fuel Tank and replace the Fuel Pump and/or the Fuel Level Sending Unit. But considering the close to $10,000 i have put into this truck in the past 4 Years and the probably 5 to $8,000 more im going to have to put into it for "Normal" maintenance (Especially since i drive Literally across the Country from coast to coast, Massachusetts to Idaho to Washington State and Oregon and Back home to Massachusetts) i would rather be safe than sorry and have some simple $1,000 silly or easily predictable repair cause $1,000's more worth of unnecessary damage AND possibly getting stuck somewhere dangerous and quite possibly life threatening in the middle of Winter or Summer somewhere in Wyoming or Nebraska with Zero Cell Phone service and Extreme weather conditions with no way to get help. But getting slightly off topic here,,, I'm really just curious if anyone else has had this Exact or very Similar problem, maybe even done the same "Fix" to try and get rid of it, OR Anyone who might know of another possible fix or what might be causing the problem (Without having to drop the fuel tank) and possibly how to eliminate this issue once and for all. Thanks for any help or guidance anyone can provide. After YEARS of using these forums to become almost "Intimately" acquainted with different error codes and the inner workings of the 3rd Gen 4.6L Explorers and saving $1,000's of dollars being able to fix things on my own with information gathered specifically from this forum,,, i Finally made an account and this is actually my First Post in the forum since i couldn't find anything to definitively fix or describe what might be causing my current problem. So again thanks for any help or advice in advance, and for all the members who i have gotten help / informations from in the past.