01 f-150 missing

I have an f-150 with a 5.4 4x4 that started missing last week. The check engine light came on and I pulled the code and it said #1 cylinder was miss firing. I then changed the coil on that cylinder. This did not help so I then replaced the plug in that cylinder because of time restraints. I thought it was better then it started missing again so I figured it needed new plugs. I changed all plugs this morning and it ran good for a little ways and now it is missing again. The check engine light come on again and the code came up as follows. p0401 exhaust gas recirculation flow insufficient detected. I have no idea where to start on this problem, any help would be greatly appreciated.

I replaced the EGR and that cleared the light, but the truck is kind of shuddering and seems to be slugish. Anyone have any ideas?

Sure you changed out #1 COP ?

I have one a year go out...mostly from water intrusion on #8

I would check the fuel pressure and check for a vacuum leak by spraying carb. cleaner around the manifold. Make sure you cleaned the passages for the EGR and check the DPFE sensor sets more egr codes than the egr.

I am positive I changed out number 1 coil.? I am going to try looking for vacuum leaks this weekend and will trace down egr system. Between work and hurricane Ike clean up I have'nt had much time. I'm thinking that I either have a vacuum leak or fuel problem now. I think I got some bad gas that may have gotten water in it from the storm.

You can try dry gas but a lot of water you have to drain and remove.

Trying cleaning out the ports that the EGR valve gets its exhaust from and then sends it into.

Still no luck I changed the fuel pressure regulator and the rear o2 sensor. I bought a fuel pressure gauge and my pressure is reading 28 to 30 not sure what it is supposed to read. The truck idles fine just starts to miss when it is under load like going up a hill. The check engine light isn't on so my reader won't tell me anything. I have changed plugs, #1 coil (had a code for that) egr valve, fuel regultator and o2 sensor. Any one have any other ideas? I tried to change the fuel filter but can't seem to get it to pull out of the hose.

For my 1997 fuel pressure should be 35-40 KOEO and 30-45 KOER so it appears your pump isn't maintaining proper pressure. Check fuel filter you can blow through them if not plugged. Check if you have an adjustment on the pressure regulator. If an external fuel pump next to filter check if primer pump is putting out 3 to 7 psi. Use a coffee can and place under line before pump if gas flows when somebody trys to start its ok. If an intank unit you will have to drop the tank. Look on ebay for a new motorcraft pump and sock. Note the primer pump is also in the fuel tank.