i bought about 7 mo. ago from a used car lot it had a little miss that would come and go so they said they would fix it if i bought it and they did it has been runing great untill the other day went to go get dinner and it started missing,now here seems to be the symptoms.when i first start and its cold its o.k. as soon as it warms up it starts missing bad when excelerating and idleing eraticly no check engine light and when i hook up my obd11 reader theres nothing hope one of you guys can nail this one or tomorrow i get bent over at a shop thanks

 

First step I suggest is to clean the maf meter, go over routine maintenance, check grounds. Without knowing the history of the truck, and with what info you provided, it's hard to "nail it" without actually being there. Good luck with the shop.

 

the lot where i bought the truck from who has fixed it once before said he would have his mechanic put in coils for the cost of the coils(qouted me about $35 ea.)i told him lets do all 8 he said he would have the parts the next morn.......next morn i go there he checks with obd and tells me he got a po303 and po302 and a po171 and then informs me he only had 1 coil he appeard to be calling someone to bring another one 3 hours of waiting around they start on mine he said he would pull 2 & 3 and test and etc.then starts about how he wanted to let his guys go early to be with family for xmas ends up putting new coil in 3 cleaning 2 and tells me if it dont fix bring it back monday.they fire it up and its worse atleast before it had to warm up a couple blocks before mises start now its mising first thing then the c#@& sucker tells me the coil cost $65. now the origenal arrangements were with the lot owner who was not there and now dealing with his brother i paid him fiqure i will deal with owner monday. i get home after another 5-6 hour marathon on the interneti realize they had put the new coil on #7 cleand #6 and #3 was never touched so i know i can do better than that going to buy exxel set for $200.00 with life warrenty new plugs do it myself clean all sensors check vacume leaks.i will video there work for when i see owner on monday anyways merry xmas all and thanks for your replie

 

thanks for your reply maestro go back to the thread and read the fun ive got to have....lol....by the way im a drummer(no drums right now but played for years) i think i will know more shortly about tritons than i ever wanted too lol i repair computer control industriel machines for a living so i should be o k again thanks and merry xmas

 

I am having the exact same issue, just started acting up last night on my way to work. About a week ago I got a trouble code for "Engine running lean on bank 2", but it was running perfect, no signs of a problem. Last night it started stuttering and shaking while driving or at idle once it was warmed up. After work I hopped in the truck and fired it up and it ran perfect again, as soon as it warmed up it was running like crap again. I'm leaning towards this maybe being the DPFE sensor which controls the EGR valve and tells the PCM how much exhaust gas is being used. Tomorrow after I get some sleep I'm going to disconnect and plug the vacuum line from the DPFE to the EGR and see if the problem clears up, if it does I know I just need to replace my DPFE sensor. If it doesn't I'll just start working my way down the checklist of things that have been recommended to be looked at (clean MAF sensor, check for vacuum leaks etc. etc.) Let me know how things work out for you and what winds up fixing it, I'll keep you posted in your thread here about my progress.

 

I decided to take it in to AutoZone and have the codes read again just in case it threw a new code when it started running like crap. It did, now it was reading lean on both banks, and misfiring on cylinder number four. So last night I replaced the coil, boot and plug on cylinder number four, which is not fun I might add. Truck runs good now! It was running real bad, shaking and vibrating all over the place like something was gonna come off my engine. I cleared the codes and now I'm going to wait and see if it throws a code again. I also got a can of MAF cleaner and cleaned my MAF sensor and the throttlebody sensor. I might go grab a cheap fuel pressure tester from AutoZone as well, there are test ports right on the fuel rail (which seems like the only considerate thing Ford designed into this engine bay).

 

I can't speak 100% for F150's, but if they're anything like the SD's sounds like coil pack failures. They are insanely expensive if you buy them individually however all 8 can be purchased off ebay for like $100... and there is lots of good feedback on the SD forum about the ebay specials.

Also, word from the wise, DO NOT use nickel antiseize on your spark plugs when changing them. This can cause ground issues between the plug and head resulting in straining the coils and toasting em... or giving all symptoms of a bad coil when really it just doesn't get a good ground.

I may be a day late but hopefully still helpful