? about a three valve 5.4

[aperacer]

i have on 06 expedition. when trying to run at wide open thorttle the engine backfires through the intake as if it is running lean. and withe it getting colder it does it and any point over 1/2 throttle. i first noted this when the weather turned cold. then i made it worse by adding a cold air intake. the engine/truck has 58,000 miles on it. i have replaced the fuel filter, that did not change anything. when scanning for codes the only code it get is a p0300 engine misfire code.... and in the past two weeks while driving down the highway with the cruise set the engine goes into fail safe mode. the engine runs but there is no throttle actuation. if i shut the engine off and restart its fine. beings is am a chevy tard... or thats what i work on the most. i cant even find a schrader vavle to check fuel pressure.

any ideas or has anyone had this problem...

[DeckerEnt]

Mine is an 05 and it did something weird the other day. I was following a prius and this ***** was going 40 in a 55. I had no oppertunity to pass and was getting perturbed to say the least. Well, she finally turns off the road, after slowing to a turtle's pace, and I punch it. The new to me SUV revs out in first, well I let off and the truck starts acting funny. The throttle seems sluggish, no power, then the engine light starts blinking at me. I let it coast down a little, ease into the gas and the flashing light stops and all is right again. I tried to make it do it again but couldn't. Happened just that one time. I blame it on the Ky gas I put in it. Got the Exped from Ohio.
Keith

[facemelter71]

They changed the fuel over to the winter formula in most pumps.It might take it a few run cycles to clear up.Or you can add a fuel treatment to the next fillup.Thats my guess.

[Stangman]

Mine is an 05 and it did something weird the other day. I was following a prius and this ***** was going 40 in a 55. I had no oppertunity to pass and was getting perturbed to say the least. Well, she finally turns off the road, after slowing to a turtle's pace, and I punch it. The new to me SUV revs out in first, well I let off and the truck starts acting funny. The throttle seems sluggish, no power, then the engine light starts blinking at me. I let it coast down a little, ease into the gas and the flashing light stops and all is right again. I tried to make it do it again but couldn't. Happened just that one time. I blame it on the Ky gas I put in it. Got the Exped from Ohio.
Keith

It's spoiled now Keith :D

seriously though, My lincoln's engine light came on the other day after I started it up... then it went away... havent seen it since.

[05yellowgt]

What kind of CAI did you install on the Truck?

[aperacer]

air-aid used on an f-150 but fit my truck also. it was also doing this with the stock air box and related parts