ok guys lets see if u can help. i have 01 f150 5.4 and shes running rough. thought might be bad coil hook scanner on it and the code came up as po402. now this is egr valve which i changed 3 month ago and cleaned all the carbon out and changed the dpfe sensor. now its doing the same thing i just changed the egr valve again tonite butt still doing it . any ideas would be greatly helpful. I just cant see it being dpfe again. would this problem being if u ran cheap gas thanks for the help.

 

what brand egr and dpfe did you get? most aftermarket egr's dont work well for long with the older engines like my 5.0 but i'm not sure about the newer trucks. and most aftermarket dpfe's dont last long either. is it idling rough?

 

I am not sure what brand but i got it at o reilys and it doesnt have a roug idle just when i put a load on it (like at dead stop then step on it )

 

you got both parts from oreilly's? i'd recommend getting a motorcraft dpfe and start from there.

 

Did you check the tube running to your EGR? Im not familiar with the 01's but I know in my 98 all those tubes can get nasty. Also, you should check for exhaust leaks. Check your manifolds and make sure all the bolts are secure. I had one break of in my block, and I had to drill it out.. not fun.

 

Well i changed egr valve and changed dpde senser and also had a bad coil pack. when it rains it pours. I changed exhaust manifolds to headers 2 years ago because bolts broke and i know all about how fun that is .they are tight have bolt with screw tighten bolt then screw exspance the bolt so it cant loosen . Now its hesitating at dead stop but not as bad as before im thinking now maybe fuel filter . see what happens when I let the wife drive my truck everything falls apart but what can u do any ideas on the hesitation thanks for the posts and keep them coming. Shawn

 

has it ever been tuned up? was dielectric grease used? what brand plugs? how many miles? how olds the fuel filter? too much egr flow can cause some hesitations.

 

As far as your EGR...
9 out of 10 times its the DPFE sensor bad "digital pressure feedback EGR".(You want to make sure your DPFE is a motocraft part) Also ford has a problem especially on the 4.6 with the EGR ports clogging in the throttle body not letting enough flow(Best way to check this is to put a vacuum pump on the EGR with engine idling if the engine stumbles and runs rough its O.K. If not remove the throttle body and clean out the ports). You will not have vacuum on the egr at all times, because the computer controls the EGR solenoid and turns it on under loads and decel etc. You might also want to test your EGR solenoid because I would think that a EGR solenoid short would have your EGR running too often hence excessive flow. My thought would be that your stuck-open diaphragm in your EGR valve would be causing waay too much air into the intake at idle. If that is not it then im not sure about your hesitation issue.

Well, just a wild-shot but how are your 02 sensors? Bad 02 sensors can cause a lean or rich idle which IMO would be rough. If you arent being able to hold a constant throttle or idle you might want to check your throttle position sensor or Idle air control motor but more importantly your Idle air control. However if your IAC was going out it will probably throw another code. Just a thought

 

Well its all fixed It was the dpfe and the 7th and 8th coilpack .The dpfe was bad because it threw the code po402 and the coils where not working 100 percent thats why i think it didnt throw the coil code. I changed 8 cylinder and was still doing it not as bad then i changed dpfe because of code butt still doing so figured to take a long shot and change 7th cylinder and bang all better. its a huge wall off my back i hate when my trucks dont run right . Now i can play around with the 08 i just got my gryhon today what a difference. i just might be able to give my 01 a run for the money anyway thanks for the input on the threads they where all helpful thanks again Shawn

 

Yes sir your coil packs will do that to you. Atleast you got it all fixed up now. I hate it when stuff is not running right either. Gotta love programmers. And no problem we are here to help

 

Glad your problem is solved. I just wanted to mention, that an IAC can get dirty and not operate right, without throwing a code.

 

Sounds like you only fixed it temporally. Did you replace all the plugs? The coils (coil on plug or COP's not coil packs) You can get a whole set on e-bay for under a $100. You'll probably get another miss shortly.

 

yes i changed plugs to split fire about 10000 miles ago. the coilpacks have been changed also to msds but for some reason when it rains real hard every once and a while the two back ones go bad . its probably the water sits on them i guess i dont know but it happened before and will happen again

 

I agree jethat - more problems in the near future for sure. Pretty simple and cheap to correct though.

Here's one I noticed -

Split fire ??? - Those can and have cost people an engine, - get those out of their- PRONTO!!! I've seen pics of those get to hot in the chamber, melt and fall apart. Guess where the pieces go??

MSD makes good coil packs, most likley one of the best. BUT! They don't make them for the 5.4L, - in-fact, no one does. 5.4L's have COP systems and use dedicated coils - One per cylinder, -not a pack. You can run packs with a 4.6L PCM tuned to so on a 5.4L, but NOT with a 5.4L PCM. No one does that unless they swap from a 4.6L to a 5.4L engine, it doesn't make sense to.

Sounds like to me you just need to run the OEM parts and stop deferring from doing so, these products will set you get her straight =

1. Motorcraft plugs, Denso, Denso Iridium's, NGK, NGK Iridium's. Stick with those and she'll be happy.
2. OEM coils, run these and she'll be happy - http://cgi.ebay.com/ebaymotors/NEW-I...ht_2539wt_1162

Also - You have coolant leaks back by 3 & 4 ? That's a coil killer, need to fix that. A leak back there usually only leaks under pressure and it's hard to catch. It's the heater core feed and return lines. There's an in-line reducer that pressurizes the return line to help protect the heater core. This only leaks in spurts when pressurized.

BTW- There's a couple of routes you can take fixing the feed and return lines. Order OEM hoses from ford and purchase expanding clamps from Oriely's/Murrays or order 3rd party hoses and purchase the connectors separately from Rock Auto or who-ever has them. I know Rock has them. Here's some pics of the parts -



Yea, these WON'T cut into rubber and expand and contract with heat, just don't over torque -




This should get her right, works for me, -for others as well

 

Well thats saying alot. Im really not liking split fire spark plugs and now u just made it worse. So i guess i know what im doing tomorrow . you are also write on msd they are not i had them on my mustang . not sure if spelling them write but they are accels (yellow in color). Ive had them on for some time now and they lasted longer than stock ones .I have gotting better mpg with them . Now to the other topic u said it could be coolant leaking on coils (one per cylinder) wouldnt you smell it and see it getting low on coolant? and its say every 30000 or so one gos bad . but this time it was two . what about seeing it on the ground ? and if this is the problem how hard is this to do . I live in nc now and been riped off by two mechanics and dont want to go to dealer and pay the big prices just cant see to find someone reasonable and dont think zip ties are the best part for the job . thanks for the info and the answers Shawn