Help, getting 6mpg!

Quick recap.. Originally my moms 98 threw a P0171 code, system lean.. Had a crack on the manifold, replaced it.. Converter was jacked, replaced it.. Same thing. No vacuum leaks found, nothing anywhere, still using fuel like crazy. Took it to local Chrysler dealer and tried to do a complete PCM reset hoping it would relearn the fuel and maybe fix itself, no luck. Looked over everything again for 3 days, still nothing out of the norm.

After all this I figure I'd bite the bullet and take it back to the dealer and have them run a diagnostic test on it to see what they could find. They tell me its P0463 "Fuel sender volts high" and they want to drop the tank and charge me another 2-3 hours of labor just to try to find the issue. On top of that, he tells me that its really not using that much fuel, the computer just thinks it is.. really man? Throw $40 in this thing and watch it go back to empty in 30 miles and tell me its not using fuel.

I am puzzled, no idea where to go from here. I've been searching around trying to find an answer but I'm getting mixed results.. any ideas?l

Most common cause of bad fuel milage is the O2 sensors. If your exhaust manifold had a crack in it it may have helped contribute to a bad O2 sensor(s).

That was one of my first guesses but that doesn't really relate to the new code thrown?

Oh and don't forget the map sensor and the tps sensor all contribute info to the computer for the fuel system. When was the last good/full tune up. Condition of the air filter? Is the computer actually going into closed loop or staying in open loop? There are sooooo many variables that could contribute to bad fuel milage.

A quick Internet search shows others have left it alone as it only effects the fuel gauge and not the drivability of the mileage. I would unplug the wires to the tank and plug them in a couple times to get a cleaner connection and check all your grounds also. Almost all that I saw on a quick search for the code said they replaced the sening unit and all was good after that.

Whats The Temp Reading, I Had An Issue Where It Never Got Hot Enough Cuz My Tstat Was Stuck Open, Drank Gas Like crazy

Sands, that's the same as I asked above about open and closed loop. The coolant temp has a direct impact on the two. Just so you know....

didnt See It Lol.