5.4 missing and shuttering when i give it the gas at any speed.It has new plugs
and coils.Maf sensor have been cleaned.Need help!!

 

how about the EGR valve?if it is stuck open it would do the same thing.sometime you can get away with cleaning these, but usually this is a temporarry fix, and you end up replacing it.

 

it doesn,t miss at idle could it still be the egr

 

help me please

 

did you replace the boots when you did the coils? If the boots fail, it feels just like a coil. I had the same sort of problem. I put a code reader on it and got no codes. My mechanic tells me to take it to the dealer because Ford has not released the the codes to the general public. Well anyway, the dealer puts it on their reader and immediately tells me that the #6 coil is bad. They change the coil and find that the boot is all dried and cracked and the spark has been arcing through it. I had 'em replace all the boots while they were at at it. 6 bucks each. No problems since.

99 F-350 Lariat V10 4x4 CC LB SRW

 

it has new coils with new boots

 

It really sounds like it is a coil problem exploder, I had one go on my v10 at 110,000 and I thought the motor was coming apart when I gave it gas especially in higher gears(idled fine). Went to autozone and bought one for $45 and went home and swapped them out starting on the drivers side one by one and I got lucky it was the third one back under the air snorkel. Pain in the but yes, but it only takes a couple minutes per coil till you get to the hard ones in back. Otherwise the stealership will do a "Driveability Test" on it for like $70-80 and can check for the missfire while driving. Did you wash the motor recently? Could be some water in there.

 

no water in the motor and coils are 5 days old.the coils didn't fix the problem it still acts the same