I am chasing the infamous mis the 5.4's have. I have a misfire code for number 5. I have done the following:
New coil for number 5
New set of plugs and boots
New injector (per repair shop using bore scope and saw irregular spray pattern)
Switched coil to different cyl when the code came back thinking I bought a bad coil. I'm still having a rough idle and the CEL came back on for cyl number 5.

What else should I look at? Truck has 137,000 and runs strong down the road.

Thanks,
Matt

 

We're having the same issue with our 2005. We have 109k miles on it. Changed plugs within the last 500 miles.

 

Did either of you resolve this issue? Buddy of mine has an '05 with a similar problem and we are trying to fix it.

 

I finally went to my local shop after I was chasing my tail. What I found out was the roller rocker had failed and worn a groove into the cam. So I had a stuck exhaust valve. It ran awful of course. To fix it I needed a new cam,one rocker replaced. I didn't find this problem doing research on the net so I doubt it happens a lot. The truck only had 145000 miles. The plug removal and coil replacement is pretty straight forward if you follow the instructions. Good luck with it.