Loosing fuel but not visible in my 2000 Ford Expedition, also oil gauge seems to be reading high.

need to have it check for trouble codes...most auto parts will do it for free

Here is what I found for code explanations:
P1450 Self test detected excessive fuel tank vacuum
P2195 O2 sensor signal stuck
P144a possible canister purge valve problem

Hope this helps you out.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/michael_2496c4f07ad24453

Just use google ---to find any codes

2000 expedition obd2 code P1450

Ran out of gas and What?

Won't start?

Could have ruined an already worn fuel pump

Turn key on/engine off should hear pump run
for 3 or 4 seconds

Check fuel pressure if it runs with a gauge on
injector fuel rail or with a professional scan tool
data.

Try spraying the throttle body to see if it will run

Try disconnecting the battery AFTER you check for
codes,stored data, etc & write down what you get

For me it was the inertia switch had some dirt in it pulled the connector and cleaned it out and suddenly it started working after i checked and replaced everything else

Continuous Memory Diagnostic Trouble Code (DTC) P0446 or P1450 indicates that Self-Test has detected the Evaporative Emission Control System has excessive fuel tank vacuum. Also, a DTC P0446 indicates a vent control malfunction.

Possible causes:

EVAP canister purge outlet tube (EVAP canister purge valve to EVAP canister) blockages or kinks.

EVAP canister tube (fuel tank to EVAP canister) blockages or kinks.

Fuel vapor elbow on EVAP canister contaminated.

Restricted EVAP canister.

Canister vent (CV) solenoid stuck closed (partially or fully).

Plugged or contaminated CV solenoid filter.

EVAP canister purge valve stuck open.

Fuel filler cap stuck closed (no vacuum relief).

VREF circuit open in fuel tank pressure (FTP) sensor.

Damaged FTP sensor. (fuel tank pressure)

Check for kinks or bends in the fuel vapor hoses/tubes (EVAP canister purge outlet tube and EVAP canister tube).

Visually inspect EVAP canister inlet port, CV solenoid filter and canister vent hose assembly for contamination or debris.

Check CV solenoid filter for blockage or contamination.

The common things I've seen are are mud in the canister and the canister vent solenoid being shot or the wiring to the canister vent solenoid being torn off. The resistance of the solenoid should be 48-65 ohms..
Pick up a Chiltons book and will give you a diagram of where exactly you find the canister. They are like $15 at any auto store. Good luck

do it step by step
p0503
1- change vss sensor and recheck
2- check wiring of vss sensor
p1451
1- check wiring of EVAP vent
2- change Evap vent

Add the quart of oil. Oil also acts as a coolant.

P1450 = Inability of Evaporative Emission Control System to Bleed Fuel Tank.

This means you have either blockage or a leak in that system. Or possibly your charcoal canister is bad. Do you regularly top off your gas tank? This is usually what makes a charcoal canister fail.

Did you ever get a solution for this? I am having the same problem, same codes!!!