i've only cleaned 1 out before, i used a old broken throttle cable and pulled apart the strands of cable at one end and just jammed it through the tube. pipe cleaners might work.

 

That's unusual - You already cleaned these right -



The 4six is the only modular I've seen that packs these ports solid.

I believe yuh, just makin sure.

I've seem a EGR tube leak generate that code. A leaky O2 Bung can as well. Actually any leak between the EGR valve gasket and downstream cat can generate a 401, but you usually get other DTC's along with when this happens.

There is a few other tests you can do - You can suck test the EGR valve itself, this can isolate the problem to one area if test fails. Also check the EVR vac solenoid operation and voltage. One or more of your 1/8" Vac supply lines in the harness may be compromised. You an pressurize the vac harness itself to determine if a problem exists . That's if you can't find anything thru visual inspection - Might have ripped a vac boot at some point. The majority of damage to the harness I've seen in the past is over by the battery. Between that and the fire wall. Those 1/8 lines get real brittle with age and can just snap like a twig.

More info on the exhaust that came to mind. The EGR tube eventually rusts out @ the manifold connector. Cat's have split in the past, - under the heat shields as well.

Let us know what you want to check and we'll help you thru it , - if you need some.

You did clean all ports in the elbow correct? Guess we should make sure of that first. You'll find the problem, don't give up on it.

 

Yes, I cleaned those twice, lots and lots of throttle body cleaner through that area. May be a little black around the edges still but no major clogs, and if by suck test the EGR valve you mean stick a hose on the top part of it and suck on the hose then I did that the other day and stalled out the engine. Those the EGR tube looks really dang rusted down near the exhaust so maybe the flow is still comming but not enough or somethin.

I kinda have a feeling that it is either the wireing harness not hooking up to the dpfe right or something like that or one of the vac hoses has a leak somewhere.

Prolly need to invest in a volt meter to do any of the testing of that stuff wont I? Or is there some simple way I can see about turning the vac on to see if the valve opens?

 

Your missing something, you have to be. Cleaned the throttle body elbow, replaced the EGR valve and have a Ford DPFE Sensor. You are still getting a PO401.? If the exhaust is tight and your Vac harness isn't leaking. Your PCM (Trucks computer must be bad) - 401's are usually much simpler than this.

I guess take it in. Your disconnecting the battery before working under the hood on this stuff right? You most likely are, but I had to ask. -That's a must for and the system needs a fresh boot after correction/change to run adaptive strategies again. The PCM isn't going to check your work and erase KAM memory on it's own. Re-boot is required - Yea , you have to know that already, - I'm stumped as well - first time seeing this happen. Must be the comp..?

Everything's else has been covered.

 

Yeah I still need to check the vac harness and exhast there any simple tricks to checking them?

 

Vacuum Harness:

Yep - Disconnect the vac harness at the big connector between the battery and firewall. Then remove the harness completely from the engine bay. - Head over to bench with it and test with a Mighty Vac ( Mighty Vacs are cheap - (20 -30 bucks @ most 3rd party suppliers). It takes approx 10 minutes to remove harness.
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Exhaust:

A "Rigid" (brand name) step reducer for their shop vac's fits inside the tailpipe perfectly. With a adjustable (pencil type) blowing tool, open the pencil about a third of the way, then push into the Rigid reducer that you have inserted into the tail pipe.

With a Windex type spray bottle containing regular dish soap and water, -start hitting all your exhaust joints or questionable ares where you think the system may be leaking.

Once you hit everything one good time/ go back to where you began and look for leaks (or bubbles).

You don't have to check everything, but follow that method for any seam/area you want to check. Do this w/exhaust @ ambient. (Cold testing is best) Don't do this w/motor running lol.

Good Luck!

 

Bedon did you ever find the problem, because i'm stumped and have cleaned and replaced everything as well.