We have a 98 ml320 that was recently at dealer for a problem that was diagnosed resulted in them replacing the fuel pump. They returned vehicle to me and after @ 200 miles of driving the fuel gauge still showed full and trip computer showed miles left till empty at @ 400 miles. Also the light on dash showing low fuel never came on and we stopped and put in 18.4 gallons of gas. Could dealer have left something undone or do I check fuse box. THANKS