I have an 03 EB 5.4 Expy. I changed out all the coil packs 2 days ago and when I went to leave for work I had to pump the gas to get it to start. When I put it into Drive or Reverse, it immediately stalled. It had a really rough idle sitting close to 700 RPMs. I replaced the hose and the one next to it just to be safe, idle got better but still stalled. I then proceeded to the IAC valve. Again, there was improvements but was still stalling. Today I did a transmission flush. I needed to do it anyways but had a feeling the stalling was due to bad fluid and the torque converter. After I was done, the start up was much better the first chance and it didn't stall right away but it is still doing it. I have replaced the gas cap and the pressure feedback sensor today, checked for possible vacuum leaks using break cleaner. It still struggles to start and when pressing the accelerator while in park, it stutters. It has 149k miles and in the 3 years I have owned it I have replaced the fuel pump, fuel filter, charcoal canisters, gas cap, filler neck, EGR valve, IAC, EVAP pressure sensor, Coil packs, spark plugs, and various vacuum hoses that over time were breaking. Nothing new has popped on the CEL and I am at a loss of what could be the issue.