And, I'm still throwing codes, it ran great for a day and change after the cleaning. I do not know what code (or codes) have posted after the cleaning, so I'll have to update you all in a few days when I get them read. Before the cleaning, and what clued me into the fact that my TB needed cleaning, it posted the codes for EGR Insufficient and EGR Excessive...CRAPPIER gas mileage, clinking in the rear end when I let off the accelerator (like the engine didn't realize that it needed to disengage the transmission or something, I do not believe that I have a tranny or rear end prob at this point), rough at steady (low, like 40-45 mph) speeds. WFO Throttle works fine.
What I have is a '99 F150, 5.4L, no invasive mods, only K&N Intake and Flowmaster muffler w/ dual exhaust from the muffler back.
After cleaning, it ran superb, throttle did not stick, smoother acceleration, no "clinking" in the rear end upon letting off the gas, then, as soon as the "Service Engine Soon" light came back on, rough while maintaining speed, clinking is back, I'm pissed. 3.5 hours it took me, but you could eat off of the TB when I got done (granted, I was also taking care of my, almost 4YO, son at the time).
I have a few Q's for you RKI's...(relatively knowledgeable individuals), what is an IAC and what is it's purpose? I recently found what the EGR is, but can not figure the value add. Where should I go from here, taking into account that I have not read the codes again yet, but thinking that they are going to be the same (same symptoms as before).
Thanks for all of the advice in advance, and for the site, as it has helped me diagnose several probs to date,
Sterling
PS - If more info is needed, please let me know and I can try to provide more detail.

 

I'm very interested in this as well. I'm having some similar symptoms with my truck.

 

Try the search tool. It is amazing!

https://www.f150online.com/forums/se...archid=1467663

 

IAC=Idler Air Control. What exactly it does Im not sure. How many miles is on the truck and have you changed the COP's yet. COP=Coil on Plug. The 99's dont have spark plug wires and a single coil. Each plug has its own coil. Also what are the code #'s that are being thrown? If you dont have the codes you can go to Auto Zone and they can read the codes and give you a print out.

 

Thanks for the replies guys, yes Norm, I know, I should have done a better search, the simple search that I tried with EGR and IAC returned nothing...apparently I did not do it correctly.
The current mileage is 95,500. I have not changed the COP's yet, until I read your reply, I had no idea what the "COP" that various posts were referring to was...thanks again.
I do need to get up to Auto Zone to get the exact codes, a friend works there and got the codes earlier, that lead to me cleaning the TB initially.
I did recently have the plugs and fuel filter changed...seems that when you start the wrench on these beasts, all sorts of things begin to crop up.
When I get the new (latest) codes, I'll let you all know. I reset the computer this am to clear the codes and Svc Eng Soon light, we'll see if/when they return, which I am almost 100% certain they will.
Thanks,
Sterling

 

Yes, the search tool does not allow 3 letter words. Do EGR* or IAC* instead.
Click on the link I gave above and you will find some results from people that have solved the problem.

 

I had used the search, and knew that the dpfe needs replaced. I just can't seem to find the other answer I'm looking for though, and that's if all of the above mentioned symptoms go away (such as the driveline "clunk", etc....) after replacing the dpfe and cleaning up the TB and elbow.

 

What codes ? I looked twice - did I miss something ?

 

We need to know the codes before we can tell you whats wrong.

 

I would guess he is getting P0401 and P0402 based on him saying
but hopefully he will let us know for sure.

 

Yes, that's right, I was, *was*, getting P0401, P0402 codes, it just posted another code when I went out to get lunch. Only P0401 EGR Insufficient. I guess I'm 1/2 way there, one down, one to go.

 

Have you replaced the DPFE yet? If you do, you need to get one from the dealer, aftermarket DPFE's are junk.

 

No, I have not started replacing anything yet, just cleaned the throttle body. I need to get the DPFE, I figured that'd be my next step. I hear that there are two, the "old" style and "new", I would assume that I need the "new" style, is there a part number that anyone has handy that I can tell the Ford parts guy to make both out lives a little easier?
I am now considering replacing the COP's and wires and also cleaning the MAF sensor, just to be on the safe side. I also probably need to check the tube leading from the EGR to the exhaust manifold, I have heard that could become clogged as well (I think that'll be the last thing I do, unless someone here suggests differently).
Is there anything that I have not planned to cover thus far?
Thanks so far for everyone's help, I really appreciate it.
Sterling

 

I just replaced the DPFE on my 2000 w/4.6. Part # for the updated sensor is F77Z-9J460-AB. First, I cleaned the EGR ports in the intake elbow, but that didn't clear the code. So far, 130 miles with the new sensor, and no code. My truck was also running rough like you described. I changed back to Motorcraft plugs and replaced the boots on the cop's, with a generous amount of dialectric grease added. Running pretty good now. I got my sensor from directfordparts.com and saved a quite a bit from the local dealer.

 

I finally went to the Parts Dep't today, found out that the part not only changed once, it has apparently changed about 10 times since it's inception. The current part # for the '99 5.4L is: F77Z-9J460-AB, as Dubble Dee stated above. Ford wants $129.00 for it! NO F'ing way. I located one on E-Bay and bid on it, auction closes in 4 days. With any luck, I'll get the part and install it post haste. I'll let you folks know how it goes.
Sterling