Went out in the galaxy last night ( 2. ghia v6 petrol , manual ) and it drove fine , Got to tesco, went in to do a bit of shopping, came out , car started fine and drove off, noticed the fuel gauge needle was showing empty and ornage empty light was on, but had half a tank ,so switched off ,and on and the gauge started working properly again but car is now sluggish, noisy and seems like it will stall everytime i stop, ( not sure if exsaust is now louder ) Is there anything electrical i can check or was the non working gauge a coincedence?