PONTIAC GRAND PRIX P CODES (POWERTRAIN) P0400 - P0499

Hi. Well My Question Is The Code P0420, What Would Cause This Code To Show Up. I Have Went Through And Checked For Vaccum Leaks And...

My Service Engine Soon Light Came On. Code: P0401, I Bought A New Egr I Had The Code Reset. On The Way Back Home, The Service Engine...

Is There A Picture Of Where The Sensor Is On The Fuel Tank, A Diagram Or Something