I just replaced the fuel filter 2 weeks ago, and it actually runs worse with the new one. Thing is, I am getting an EGR code, not a fuel system code. I will check it tomorrow. I will also check the vacuum lines to and from the electronic vacuum regulator. I'm thinking that maybe if a vacuum line is busted from the intake to the regulator, its not going to get vacuum to pull the diaphragm up. But the code description is "egr valve open at idle". If the diaphragm would be broken, wouldn't that be a major vacuum leak, cause my surge and hesitation, and then my non illuminated code?