trying to fix a misfire

[Russell103]

I have a 98 F150. Two moths ago my truck started to misfire on more than one cylender. Have replased spark plugs and wires still misfire. used code reader cylinder 4 and 6 misfire. Changed both coil packes. Ran great for a week then started to sputter, Check engin light came on. Uesd code reader said P0305 witch is cylinder 5 misfire. Changed injecter last night 5/1/12. sputterd when first turned on but no engine light. ran rough for 2 to 3 minutes then ran great for many miles so i parked it. got up this morning went to work ran great for about ten miles and then started to sputter. check ingen light on. I NEED HELP

[Bluegrass 7]

Russ, ya got to just chase each code as they come up because you have been working on the system and may have even created some issue.
You will get it all cleared with some patience.
Hang in there.
Good luck.

[Russell103]

is it normal to some times to do that, bc i have been doing my own work on my car for 10 years and never ran into problems like this.

[Bluegrass 7]

Sure. You can sometimes chase the fox when he is faster than you until you get him cornered.
Your working on a total computer controlled system that you need to know more about when the fault become elusive.
The designers at this point did not put in the program anything other than codes for which you need to know about how they are fault generated.
Too many owners fly off with the first familuar words they see and waist money on a part they may not need.
The Ford discription of the fault and the causes are the key to looking at the hardwere for the source of the problem.
Many actions are interdependent such that the end result is a code that was the only way the system could tell the outside world what may have happened in some other part of the system that affected the table issuing the code.
This means you have to look in the associated areas sometimes for the fault.
You always go with the latest codes set for trouble shooting and never old history.
If you do, confusion comes into play.
And it's doubley tough when two faults are present at the same time and is not recognized as such.
Good luck.

[Russell103]

thanks, i went ahead and bought a obo code reader and it is saying P0305 so that is telling me it is the same cylinder so im going to back track from were i ended and hope that the coil pack might be faulty because the code was not showing before i changed it.

[Russell103]

I figuered it out. How it happend I dont know but some how the spark plug was burnt up from top to bottom and they were only a mounth old. so my advise to everyone do not buy Autolite plugs