Problem with engine after I put 02 censors on.

I put 02 censors on and ran the car ten miles and came back home . And on my gas gage all lines were gone n didn't run out of gas but turned off car and started it again just to make sure the car was ok and not out of gas! I didn't start it for 2 days n now she won't start I put 2 gallons of gas in and it won't start I put fuel injector stp in it with the gas and she still won't start she turns over n wants to start I even put fuel in the motor and it starts but won't stay running please help me I really love this car I've done a lot of work to it and hate to get rid of it