I have a 2001Ford Expedition 5.4L Eddie Bauer edition, and I'm having persistent cylinder 7 issues. It started about asix weeks ago. Since it has started, I have replaced all of the coil packs, plugs injectors and ignition module. It started smelling like the cats were getting hot. And then all of this trouble. Can someone please help me out on how to fix it? It's driving me crazy.

 

How many miles on the engine? Check the compression to verify it is okay. Check the cats for back pressure. Muffler shops can do this easily.

 

Do what roadie suggests.

You can do a quick (but not thorough) test of your cats by banging on them. If they make a lot of rattling noises, chances are they are shot.

Secondly, I recommend Motorcraft plugs, coils and injectors for this engine.

Lastly, what are the codes you are getting and how many miles?