Proton satria neo 007,fuel guage problem,it will show gas level and then suddelnly the guage will go down and stay there showing no gas and the petrol light dont even work

You need to determine if the sender is bad or the gauge is. If you can get to the signal wire at the fuel tank for the gauge (this goes inside tank to sender that provides a variable ground circuit) ground that wire briefly to see if dash gauge rises. If so, part inside tank is bad. If not, gauge or some part of its wiring circuit is bad.