hey this site is great thanks for the info...my 99 expedition with the 5.4 is chugging at 30-45 mph when bairly on the gas..one of the hoses on the dpfe was off and i reconnected it but still does it, ijust did a full tune up and checked all coils ans replaced the fuel filter...what do you think

Hi
I recently changed the plugs and COPs on my 99 Expy and it ran like a champ. A few weeks later, I am having the exact same problem you are having. Did you ever determine what was causing the problem?

Thanks
Dave