06 Etec 200 Ho (E200 DHLSDF)

Well, found out the hard way that the fuel remaining gauge is not 100% accurate, OOPS! Ran out of gas! After I switched over to the other tank, the motor would not start. Primed motor again, then just started, revved up real high and shut down. Did this a few times. Also the system check began to alternate between check engine and low/no oil, but with no alarm. I primed oil bulb, after a few attempts the motor ran fine. Drove it for 20 or so minutes with no problems EXCEPT the fuel flow is now WAAAAY off. At 3/4 throttle it says I'm only using 0.9 gallons/hour. Other than that motor was back to normal. I assume this is a "glitch" and not to worry about it too much. Also can I just re-calibrate the flow by clearing the total fuel used and then adjust it again after I use an exact amount of gas (ie. I put in 10 gallons, after I use it up I go adjust the t. fuel used to 10). This is what the manual says. Thanks for the help.-Joe