Hi,

97 F150, 4.6L, XLT. I had the check engine light coming on and off for a while now. Code pulled each time was PO401. I bought a new gas cap to try the easy fix - CEL came back. I was trying to avoid getting at the EGR and DPFE because I am new to this.

But I decided to try it today. I replaced the DPFE with a new one - so hopefully that will fix it. But, in the mean time, I thought I'd at least remove tghe EGR and clean the ports. Well, in the process of removing the EGR, I broke the head off the bolt closest to the front of the engine. Now what?

I'd imagine I am never getting that EGR off? Also, the big nut on the back of the EGR - that was tight as hell. What should I do about that? I hope this doesn't sound stupid, but if I am facing the windshield and am trying to get that nut loose, which way do I turn - right or left? I'm just making sure because I am afraid I'm going to break that too!

Thanks for any advice!

 

Facing windshield go right.
Probably gonna have to pull the upper intake to clean the egr ports properly..
I would get a vacuum tester and pull a vacuum on the egr before pulliing the upper intake..
If it stalls the truck once vacuum is applied, no problem with the egr ports.. Most likely the DPFE sensor should do it..

Good Luck and keep us posted..


FordMasterTech

 

Will do.

Also, I just got back from autozone and got my code cleared. While there, I bought a can of carb cleaner. I figured if I can't get at the EGR to clean the ports, maybe this would do it.

My question is: 1) Will this do it? Will it help at all? and 2) if yes - where do I spray it?

I know this is basic stuff, but I'm new to do-it-myself fixing, so I appreciate everyones help - I'd be lost without this site!

Thanks!

 

That wont help at all... Like stated above, the most common cause of P0401 is the DPFE. Soak the large nut with PB, or some other type of penetrante. I soak them, loosen untill it gets super hard again, then spray, then tighten, loosen, tighten, back and forth ect... Keep spraying it. It will come off, just takes some time.
Also pull the hoses off the DPFE, (carefully, those silly hoses are expensive) make sure the hoses are clear of any obstructions. I change out on average of 2 DPFE sensors a month.

Hak

 

Don't use carb cleaner on any thing under the hood of your truck! It will do more harm than good in the long run.

You want to get "Intake" cleaner. make sure it says that it is "coating safe"

Other than that what HAK says is cool.

 

Hi Folks,

Thanks for all the replies. Ok, based on what you have said, i won't even bother with the carb/intake cleaner - sounds like it won't help at all.

In the mean time, here's what has happened. So, the new DPFE is in, but the CEL came back on after I took her for a spin.

I put a vacuum on the EGR valve itself (I disconnected the green tube from the top of the EGR and applied the vacuum there). It held pressure and while running, she did NOT stall at all.

So does that mean the ports are blocked?

I then reconnected the green tube to the top of the EGR, and disconnected the other end of it - attached to something else, I'm not sure what that is. Anyway, I applied vacuum to the tube itself, and it held pressure - so I guess there are no cracks in the green tubing.

At that end of the tubing, there is also a white tube. I applied vacuum to that white tube and it did NOT hold pressure.

Does that mean anything? Thanks for everyones help - at this point, I am determined to fix this myself - it's a matter of pride now!!!

 

Get any small bottle with a cap and lay it next to your bolt and what ever way you turn the cap to open the bottle is the same way to turn the nut or bolt to loosen

 

It means either the ports are blocked or the EGR valve is bad. Odds are better than 99 of 100 that it is the clogged ports. Time to clean them.

"Lefty loosie - righty tighty" as viewed from the end of the fastener. Works for almost everything unless reverse threaded.

Use PB Blaster to loosen rusted/corroded fasteners. It's like Liquid Wrench on steroids.

Steve

 

Like the prior post, I agree..

CLEAN THEM PORTS!!

Good Luck!!


FordMasterTech