I have a 2004 gt and it keeps telling me to check the gas cap. I have replaced it thinking that the cap was bad, but I have put an autozone gas cap and a cap from a pontiac dealer on it but it still reads check the gas cap. I dont smell gas under the car and the hose clamps I can see for the filler are tight.I have also hooked it up to a code reader and nothing about fuel,just a coolant sensor witch I replaced. I have to take it through emissions and I know with the car reading that It will not pass. please help