I have a 2004 F15- with the 5.4 I have a problem that I posted several months ago and some suggestions were made. I did the work and the problem is still there. first, there are no check engine lights....the truck makes a bogging noise when at speed and slight pressure on the gas pedal. Worse at highway speeds. It's a low noise and the truck lacks power. I get on the gas and it all goes away and runs fine. since the last posting I have changed the plugs, wow what a hassle....run sea foam through the engine, did a vacuum check. All checked out good. This has been going on for probably a year now.

 

Clean MAF sensor with MAF cleaner. And clean the Throttle body.

 

Same problem here. Throttle body and MAF cleaned in addition to new plugs. Recently replaced 2 plugs and getting ready to do the remaining 6. Out of feasible ideas.

 

When all was changed did you disconnect the battery for approx 30mins. The computer needs to be reset so it can "relearn so to say"

 

I did clean the throttle body though I may do it again. What is the best way to do that? What is MAF? I did disconnect the battery when changing the plugs because I had to remove the computer. thanks

 

MAF "mass air flow sensor"= This is located in the intake tube before the air filter. It takes a star bit to remove it. Pull it out and spray MAF cleaner in ever angle to make sure there isnt sh*t on the fins/flow indicators. To clean the TB you can use brake cleaner/carb choke cleaner. Really anything that will remove the residue that is on the surface and wipe it off and blow it clean.

 

Check the function of the throttle pedal switch. Check the thing for proper resistance throughout the range of motion. If you get an "ol" reading at anytime when measuring resistance, the switch is bad. When my friends truck had this problem, it acted the same, but his is an '10 model and the wrench light accompanied the concern. Hope this helps.