I have an '04 impala and the gas and temp gauges are off. the temp gauge is way down pointing at 6 oclock and doesnt move much. the gas gauge is all over the place I can turn the key on one time and it says half a tank and then turn it off and on again and it will say like a quarter of a tank and it is always different everytime I trun the car on. The speedometer seems to be fine just the other two gausges. any ideas?