I have a 2008 Silverado 3500 HD with the 6.6 duramax. It has close to 200,000 miles on it and recently it has been reducing my engine power and saying I have 0% fuel filter life. it seems to do this only when I am towing. I have changed fuel filters and that does not seem to help. I am wondering if it could be the fuel pump. has this happened to any one else, or does anyone know a solution?