When the CEL came on, I took the car (MY '99 2.2L OBS) to the dealership to have the code read. The Inspect & Report sheet states: "A&B Code P0463". I looked up the code. It translates to 'Fuel Level Sensor Circuit High Input'

Their suggested course of action is to replace both sensors in the fuel tank. Prior to CEL, the gas gauge would occasionally act funny. Indicating an nearly empty tank when it was still 1/4 full. Once the Empty Fuel light came on when I had a full tank. But since the mechanic reset it, the gauge has been operating normally. What would you guys suggest?

If I had the parts & new gaskets, how difficult is it to replace myself?

I had the same exact problem happen today on my '99 2.2 OBS.
I refered to my handy haynes manual and read something about the fuel level sending unit. I'm going to make sure the conections are good. I thought maybe some moisture got on them.

If that doesn't work I'll probably have to replace the sending unit. I called a dealer for parts info. They said to replace both sensors, one at $87 and the second at $69, ouch. There is also a gasket where the unit mounts on to the tank. I'll probably replace that too.

Thats funny. Those prices were WAY lower than what they quoted me. The dealership said one sensor was built into a module that also contained the fuel pump and the whole thing had to be replaced. This single module was something to the tune of $320; and that was just one sensor. The other weighed in at $60 or 70.

How detailed is that Haynes manual? Do we have to replace gaskets too? Specified torque ratings on the screws to remove? After replacing the sensor, do we have to do something to the onboard computer as well?

well my manual is for the legacy 1990 through 1998 but most of what i have seen in it is helpful. As for the sending unit basically it says to unscrew it, pull it out (at an angle so not to damage the float arm), unscrew the mounting bolt on the sensor, replace the sensor and put it all back together. I would replace the gasket to be on the safe side. Haynes doesn't say anything about two sensors though.
On another note my problem has stopped for now so i don't think I'll be dropping any cash on those parts right now.