Sputtering Engine, possible misfire.

[hampton_25]

I have just recently came upon a problem with my 03 5.4L engine w/111k miles. About a week ago while I was on a road trip the truck started sputtering when we were going up a hill, like it wasn't firing on one of the cylinders. My wife said it was exactly like when the #8 coil went bad. On the trip back home it would come and go, during the two hour trip it probably happened 4 times to us lasting no more than 10 miles.


Now it happens a lot more often. You can hear the exhaust sputtering when taking off, and when I am at a cruising speed and go to accelerate it starts missing again and there is an extreme loss of power. When I am sitting in the driveway and revving the engine it doesn't happen, the only thing that I notice is that in between the 1000 and 2000 RPM's the engine has an odd vibration to it, but no significant missing. I don't have a check engine light so at this point I am really scratching my head. From all the post's that I have read when someone has a bad coil the get a code from the CEL.

A little history on the engine, I changed the plugs last year at approximately 95k miles, and since then I have had one blow out, and two coils replaced.

So here is what I would like to know.
Does it sound like a coil is bad or is it possibly something else?
If it is a coil, how do I test for a bad coil without a CEL code?