1997 Ford F-250 P0453 and P0455: Fuel Tank Pressure Sensor Failure and Vacuum Leak Diagnosis

Approximately one year ago, I replaced the fuel tank on my 1997 Ford F-250. After the replacement, the truck passed inspection and operated normally until about a month ago when a check engine light came on with code P0455 — indicating a serious evaporative system leak. I performed a pressurization test on the fuel tank and inspected all hoses and fittings. The diagnosis revealed that the fuel tank pressure sensor was cracked. I replaced it with a new one purchased from eBay, but shortly after installation, the truck displayed code P0453 — 'Fuel Tank Pressure Sensor Circuit Malfunction' — while no longer showing P0455. I found online that some new sensors may initially register high readings due to manufacturing tolerances. I attempted this by gently tapping the sensor with a screwdriver, which temporarily resolved the issue for several miles. However, the P0453 code returned shortly after. I then reinstalled the original cracked sensor using epoxy and cleared the code. For about 20 miles, no errors appeared. But upon turning off the engine and restarting it, the P0453 code reappeared immediately. I removed the gas cap and covered the opening with Saran wrap. While the truck was running, I observed a noticeable vacuum inside the tank — confirming that the evaporative system is active and functioning under vacuum pressure. There are no visible leaks in other parts of the system. I also hear a distinct 'purring' sound from the throttle body after shutdown, which lasts about 20 seconds before fading away — consistent with a vacuum line or sensor issue. I'm now unsure whether this is due to two faulty sensors or an underlying engine-side circuit problem. The truck runs normally otherwise, but I need expert input on how to properly diagnose and resolve the P0453 and P0455 codes in my 1997 Ford F-250. Any advice or insights would be greatly appreciated.