Several annoying problems at once!

[ANDREY_92]

so basically i started my car up and then to find out the engine managment light was on along with my speedo not working and my petrol gauge deciding to go to empty everytime i corner or hit a speed bump! and if hat wasnt bad enough the next day the airbag light comes on!

so checked the car on diagnostics and the only thing that is coming up is the 'exhaust gas regulation valve' code 'P0403'. but i want to find out what is causing the the rest of the problems before i start spending money on the valve. can anyone help please asap

 

[Pyro]

Sounds like a dodgey earth in the dash mate

 

[ab1702_123]

iv had the problem with the speedo not working and petrol gauge going off whenever u go round a corner or over a bump,when the bloke at garage sorted it he said there was i wire earthing out under battery and also some sort off plug/sensor had melted/corroded but i cant for the life of me remember what he said it was called but it wasnt a too expensive fix.if anyone says it the clocks get a second opinion as that is what happened to me at first.