Ok so I took a 400mile trip this weekend. I went from 2000ft of elevation to 8000ft and temp was a high of 50* to a low of 14*.On the way there I was running round 75-85mph. The check engine light came on(it was blinking for about 10 seconds) once on the way up.

Running around town the truck was fine, but on the way back it came on about 10 times. So I stopped to plug in my can tune.

The codes where
P0300
P0301
P0302
P0553

The truck lost power and mpg went down a lot.
Once I got back around my town the truck runs fine again.


I have a 2004 5.4 2wd 104,000 miles,With just bolt ons I replaced the spark plugs around 10000 miles ago but never replaced the coils.

Has any one experienced this?

Thanks for any info!!

 

Any one ??

 

Thanks every one. I know this thread is not about lifting my truck 12 inches or about slapping 37s on 22x12 inch wheels but ****!!

Seems like this forums gets crappier by the day..

 

I just posted a topic about the c.o.p coils but mine is a little different problem than yours. Any info i get i will pass your way.

 

Thanks I appreciate it.

 

The first place to start with a misfire problem is the coils. Lookup the code or go to your local auto store they most likely have cheap or free code reading. Whatever cylinder is giving u probs will most likely say which coil is bad. My edge did and i replaced one coil and not a problem since 20,000 miles

 

What plugs did you use? I've heard of Champions crapping out after that many miles but mine have been good to go thus far.

Have you checked into the usual maintenance stuff? FPDM? Fuel Filter? Air Filter? MAF? Throttle body?

 

I used motorcrafted. Ill change the fuel filter this weekend and check the maf.

 

I had a similar problem with mine . Same symptoms .
Had replaced the plugs about 400 miles previously .
It threw a code ( sorry I don't remember the exact number ) "Misfire Cylinder 2" I think it was .
Replaced the COP's and problem solved . Truck runs great .
104,000 probably time to replace them .

 

What are cop? The coil boots??