I have 98 f150 with a 5.4 in it ,and the problem im having is when i get up to 50 to 60 mph it tends to cut out ,the rpms jump up to 300 rpms and then back to normal ,it idles fine and driving around town is fine ,not sure what is causing this ,changed the fuel filter ,and my tbs checked out ok and there is no cel anybody have any ideas thanks

 

do you think it might be a bad cop the truck has 144000 miles on it and i bought it 2 years ago and i have never replaced them, could this be a symptom?

 

which forum should I reply on???

 

yeah i like to cover my bases ,saw your post on the other site idont think the plugs have ever been changed but wouldnt it throw a code if a cop or plug was bad?

 

not always