First - thank you to FordPwr for his pictures and advice. I just fixed my DTC P0401 problem by cleaning the coke crap out of my throttle body. The pics in FordPwr's album helped a lot. I posted six detailed pics in my album:

https://www.f150online.com/galleries...TOKEN=75689360

My disclaimer!! I am not a mechanic, nor do I have any training as such. This is just what I did. Miraculously, my truck still runs and I didn't have any screws or bolts left over when the job was done. The fact that I didn't have any parts left over shocked the heck out of me as this doesn't usually happen ...

Here's my hints:

1. You only need to remove 9 bolts and 1 nut to do this job. (Hmm .. maybe that's why there's no parts left over ..)
2. Remove the three bolts holding the plastic housing over the throttle body.
3. Remove plastic air intake.
4. Remove the single nut holding the vacuum hose to the power brakes. Note that this nut screws on to an interesting double ended bolt. The bolt has threads on both sides. You remove the nut first, then remove the bolt using an extended 10 mm socket.
5. Remove the second bolt holding on the The DPF (differential pressure) sensor. Noticed that in FordPwr's pictures, he did not do this, but I found it MUCH easier to clean the throttle body if you do. It's important that you remove these two bolts first as they are difficult to remove when the throttle body is removed from the engine.
6. Remove all the hoses. A light touch with a screwdriver might help here.
7. Remove the last four bolts holding on the throttle body elbow.

Clean the coke crap out and reassemble. I did not have to replace any gaskets when I did this. I did notice that on my 1999 F-150, the gas line was starting to degrade, but I did not replace it yet. I will continue to check it and I might do it in the future.

I had to remove the negative battery terminal for a little while to make the check engine light go away. Now that it's off, it hasn't come back on.

Greg

 

Here's a great write up that I found .... after I completed the job!

http://www.fordf150.net/howto/throttlebodyclean.php


Regarding the cruse control cable. It 'clicks' on to the throttle body. You just have to open the throttle a little bit then push the cable away from you forcefully. It required quite a bit of grunting to have to have it pop off, but it does come off without the use of any tools. I thought I was going to break it, but turns out that forcing it was the right thing to do.

You do need a 10 mm deep socket to do this job. Make sure you have one before you start. A universal joint helps a lot also.

G.

 

Blast from the past. No wonder i have over 3000 views on those two pics
Glad i could help everyone out. Wife now has a 2004 expedition with 4.6l miles. Its been running fine so far.

 

Ok guys\gals. I chilled 18 long necks of my favorite bud, and put on a pot of coffee. Removed the throttle body OMG (oh my gawd.) Then I remembered my truck 1997 f-150 Screw *Bessie* has 163,000 miles. Both egr ports were blocked well over 95 percent. I saw a hole in the petroleum hash, or carbon build up. HEE HEE that was for the people that where active in the 60’s. Anyway, dug out the hash\carbon with a set of Allen wrenches. I slowly graduated sizes until I cleaned them out. I can see now why I would get a PO401 (egr flow insufficient.) After a few shots of break\carburetor cleaner all done. Seems to run better, neither codes nor any pending. Therefore, I will cross my fingers. I will say I am disappointed that it I did not do it sooner. I figured since I was a BUNDY (family member from a popular TV show) that the gasket would break or be brittle but NOPE. It all came apart clean. No alcohol was needed, well to consume anyway. Ping is slight now; of course, our gas is chit here. Oh, I did clean my MAF (massive air sensor) last week. New air filter and fuel filter as well Plugs were done about a month ago or something. So add ole Jed Clamp’it, to the list of egr port cleaning survivors

 

I cleaned my TB today after reading these post.
I followed these instructions and everything went pretty smooth.
The driver side TB bolts are a bi-atch to get to, and I dropped one into the motor somewhere (not down the intake though!). Hope that doesn't come back to huant me.

Have a deep-well 10mm, extensions of all sizes, a swivel, and an 8mm socket on hand. A screwdriver helps pry off hoses.
I unhooked the cruise control cable at the far end as in the link above.

One port was full blocked. The carbon hardens and REALLY seals off these ports. My other port was only 20% blocked I'd estimate.

I cleaned/lubed the IAC as in the instructions. Funny, I don't even know what the IAC is/does, but it was easy to do at the same time.

Truck seems smoother, but I only drove a few miles since the cleaning.
I'm going to tackle the plugs next.

Thanks for all the great info in this thread guys.

~ Jim Meyer

 

Cool man, can't wait to tear into mine. How many miles?

 

91k

Are the spark plugs pretty easy to change??
Should I do wires at the same time??

 

No the plugs are not what I would call "easy" to change, but there far easier then the 5.4. I have changed the plugs on my 4.6 3 times now, takes me around 1 - 1 1/2hrs 1st time it took at least 4.. If you can do the TB cleaning you can change the plugs, just give yourself some time. Also do a search, some
guys have had some very helpful hints as farr as what sockets & extensions to use, I dont remember them or i'd tell ya, I just use what I have on hand.

 

Remember if you are cleaning your MAF to use electrical contact cleaner
they sell a brand call CRC at Autozone, spray it down good and just let it dry, don't ever touch the two small heating elements oil form your hands, or fuzz from at paper towel will ruin them ( Costly ). I once had a hair between the two wires and made my 2000 sable run like crap

 

Can anyone tell me the torque specs required for the job? Thanks.

 

I never reset the computer after cleaning the tb.
I had run some injector cleaner through my tank too.

I just left the neg battery cable unhooked for 10-15 minutes, and it feels even better.

Need to do more testing.
Has anyone else noticed good results from resetting??

 

I know this is an old post, but I just wanted to say thanks. This thread was most instrumental in helping me resolve the P401 "Insufficient EGR Flow" code. I have a 2000 4.6L. I had been putting up with this code off and on for 2 years. In the past, when it came time for emission tests, I'd catch it when the CEL was off. This year, the CEL never went off. From the pics in my album, the throttle body EGR passages were completely clogged with carbon. Opening up these passages cured my P401 issue.