Hello all, new to F150 forum. Anyway, I have a 2007 F150 XLT that has 43,000 miles on it. Last month as I was driving up a grade, the engine light flashed at me a few times and I lost a little power. (First time my truck has done this). Since then, it seems like whenever I drive up any kind of grade it does this. SO we checked the computer, and it said PO355 ( or something like that) which basically means misfire on 1. Checked the plug and it was good and to the best and most advice, changed the coil pack on 1. Still does it. In fact, i even changed 5 because i thought i might have changed the wrong cylinder. We also did a compression check and that reads to factory specs. Injectors maybe? Should I replace all the plugs and/or coil packs? I have power from 0-60 and city driving....no problems. But when I get on the freeway and reach 60 plus mph or 3000 rpms and step on it, the truck loses a little power and that light comes on. Any thoughts???? Thanks guys.....Keith

 

First thing I would do is try a higher grade of gas and see if the truck is still doing it.

 

P0355 error code is a coil primary/secondary fault on cylinder E, #5. If the problem persists with a new coil, then there may be fault in the ignition controller module.

Try cleaning the sensor electrodes in the MAF module.

 

Thanks guys....actually took the truck to the dealer to see if warranty issues are in play. Will keep you updated. Thanks again for the suggestions.