Posting this thread for a friend with a 2004 FX4 with 5.4 with 60,000 miles. runs great until he slows to about 1,300 RPM on the highway and then when he steps on the gas again it cant decide whether or not to downshift and goes back and forth between OD and drive. Totally stock truck. Any suggestions will be helpful.

 

He must have ended up with one of the female F-150's (they are just indecisive by nature).

Sorry I can't offer anything helpful.:o

 

change the spark plugs (MotorCraft) and that should fix it. mine did the same thing.

 

Take it to the dealer for a spark plug change unless you are very familiar with the 2 piece plug issues on that engine.

 

Definitly change the spark plugs out. If you decide to change them yourself and run into an issue where the "tip" of the plug stays stuck or breaks, Matco makes a tool just for this that runs about $150 that i found extremely useful and worked out great. I had the same problem with the bucking and the plugs cleared it up, but be prepared to spend some time under the hood. Even if you opt to take it to the dealer and they break on them i've heard of the dealer trying to stick it to the truck owner for the head removal.