2003 5.4 4wd stumbling on acceleration

I have an expedition with about 75k miles on it, it has ran perfect since I bought it used with about 30k but just started missing or stumbling on acceleration. It hasn't triggered the CEL yet- I put a bottle of fuel injector cleaner in it but there has been no noticeable change. I drove it from Orlando to Tampa on Saturday and it was fine on the highway cruising- it was only under accelaration that you could feel it stumble. I noticed it after I filled up last time- do you think it's possible that a bad tank of gas could cause this? Do the coil packs go out wothout triggering a code? Any ideas would be appreciated. Also- the plugs haven't been changed since I have owned it- I guess I could start there.

You could have a bad tank of gas. Also there should be a pending code in the system to point you to the correct cylinder. It is possible to have an ignition misfire and not trip a code. Plugs are a good place to start. Look at the coil boots closely foe=r signe of arcing through the boot to the head.

Thanks- good to know that a code could be stored if I never saw the CEL come on. I will head to Autozone as soon as I can and post what i find out

I'm leaning towards the coil side. It could do this without a CEL.

Working a similar problem in a 2001 with the 5.4L. No light, no pending codes.... I'd like to pull plugs and see if I can find a fouled one, but it is such bitch on this vehicle. Waiting for a light/code to appear....

I have an update on my situation. After driving it like this for about 2 months I finally changed the plugs and coil packs- situation is fixed. It never died or caused any major problems- just felt like the fuel injectors were extremely clogged upon acceleration. I did not have to loosen my fuel rails to get to the plugs/coils- I used a set of wobble extensions and took my time (about 3 hours). The most difficult one was the rear cylinder passenger side. I followed somebody's tip I read online to blow each plug well out w/compressed air (used a very flexible small hose attached to my nozzle) before removing the plug- very important because there was an lot of loose dirt down there. Also after reading some good reviews about buying aftermarket coil packs from a company on Ebay, I purchased an 8-pack of them for around $85 including shipping. The company was called GLobal Automotive and the parts were titled: NEW IGNITION COILS 97-05 FORD EXPEDITION V8 DG508 (8). Also there is a good pictorial that a guy put together here: http://www.angelfire.com/sd/vmkrampitz/spark_plug_change.html
Test drove it and it ran like a 5.4 should! Thanks for everybody's help!

Thanks for taking the time to post a fixed post. Now we can all go have a beverage of our choice with the pay we get. There is just not enough posters that take the time to post what fixed the problem. Thanks again.

I was getting ready to mention the coils when I read the "rest of the story." Congrats on the fix. Thanks for the addendum to the story. I bought a similar set of coils from eBay. Been on there a while with no problem. The plug you mentioned I NEVER got out. I spent about two days with every configuration you can imagine and the plug socket would not settle on the plug. I used a small air hose to blow out around it. No luck. Finally opted to just change the coil and let it ride. Been running great since. Also wanted to mention the "leakage" problem associated with some of the Expeditions. Heater hose seeps right over that plug and causes the coil to fail. Double check that area when you can to ensure there is no leakage.