Expedition: 1999, 5.4L

I recently had my car inspected and it "Failed" throwing code P0401. Before it will check out the code will have clear. The mechanic said it would be $300 - $500 to fix. In reading the posts in this site I am seeing the replacement or checking of everything from the EGR valve to the DPFE (EVR) Solenoid. I am on a budget so I would like to replace one first to see if it works. I have ordered the EGR valve but what would you guys suggest as to the best starting point? Is the problem "usually" the EGR or DPFE or is it a crap shoot?

Immediate Help is needed. The wife is driving a truck in need of an inspection and I have not told her yet... I am sure you can understand.

 

SOMEBODY WANTS TO MAKE MONEY,FAST. Most codes PO401 is because EGR gas can't reach internal engine. Cause, blocked ports into it. Apply vacuum to EGR VALVE AND LISTEN TO ENGINE(RUNNING OFCOURSE) . If it dies or idles real slow the ports aren't plugged. Can be delt with a hole lot less than your big money guestimate. Does this help. Good luck.

 

Thanks for your quick reply. However, and I know this may sound like a "stupid" question but what kind of "vacuum" is needed? I will assume not the "cleaning" type. In addition, can you more descriptive as to which hose you take off. The one leading into the EGR valve? and do you put the vacuum up to the hose or up to the part which you took the hose off.

I am sorry to sound ignorant ... well, I am.

Signed,

Novice "want-a-be" mechanic

 

To activate the EGR you remove the hose going to it and either use a vacuum pump or hose on the nipple of the valve and apply vacuum. You do know which valve is the EGR?

 

Thanks Luckild, I had to buy an EGR valve to see what it looks like. From there I will assume finding it is relatively easy. Unless it requires special tools to remove, I should have no problems... ha ha, famous last words.

Where do I get a "vacuum pump"? Napa?

 

Napa should be able to supply you with 1. Maybe even rent you 1. But all you really need is a piece of 3/32 hose and your mouth. Don't install egr valve,you can take it back if you don't need it.

 

Thanks. So if the truck "does not die or idle roughly" the EGR valve is OK. So would that mean the PFE Sensor is bad? Is there a way of checking this? If the PFE is not bad, any thoughts as to why the P0401 code is coming up? I could attempt to take off the battery cable (negative I think) and reset the box.

 

Change your D.P.F.E. sensor. More often than not this is the culprit.

Disconnect the battery.
Disconnect the D.P.F.E. Hoses, MAKING SURE TO MARK WHICH HOSE CAME FROM WHICH NIPPLE. 1 is Hi & 1 is Ret.
Disconnect the D.P.F.E. Electrical Connector
Unbolt the 2 8mm nuts that hold it on being careful not to drop them.
To reinstall, follow the reverse of the above.

You can look the the openings. If the looked dirty you can try to clean them out ( on the hoses and D.P.F.E.) . You can try cleaning each part that may throw that code. It is cheaper than replacing them. Try a Qtip and brake cleaner. The E.G.R., E.V.R., D.P.F.E. are each held on by 2 bolts, and easily accesible. The E.G.R. is also connected to the exhaust via a large compression fitting. Since you are budgeted I would try this approach first.

 

Lovin' the SpongeBob.

Thanks so much for taking the time to be descriptive. I already purchased the EGR valve but what I am hearing is that I may not need replace the EGR but rather the DPFE sensor. Should I purchase the DPFE sensor then, keep the EGR valve and if the code is cleared, take back the EGR valve. If it does not clear the code, then the EGR valve may also need to be replace. What does a DPFE sensor cost??

Also, I have Throttle Body cleaner, can I use this rather than brake cleaner or do you recommend brake cleaner for these parts?

 

I've heard DPFE sensor design is terrible and prone to failure. Like 1999XLT said, I'd start there.

 

Thanks buzzard!

 

I found the following response elsewhere:


Locate a short (1-2 ft) length of vacuum line.

Disconnect the vacuum line from the EGR valve and connect the short length of line.

Start engine and allow to run at idle speed.

Pretend you're trying to drink a thick milkshake and suck on the vacuum line. This will open the EGR valve.

You will get one of two response: 1) The engine will drop rpms, even to the point of stalling or 2) no change in engine rpms.

If the rpms drop, the intake passages are clear and the EGR valve is working. Concentrate your efforts on the DPFE sensor and the small vacuum lines that connect the DPFE sensor to the EGR sample tubes.

If there is no change in the rpms, proceed with disassembling the intake port for cleaning.

A simple test can point you in the right direction and to avoid what might otherwise be unneccesary work.

 

I don't know about sucking on a running engine, but.........to each his own I guess...................

 

Sounds strange to me too, especially on a part called an "exhaust gas recirculatory" valve, but I read at least four or five posts that specify the same test. One could always use a vacuum pump in lieu of the mouth.....I guess.

 

Buzzard, thanks for the reply. I too have seen in many posts the "sucking" technique. I thought a nose plunger like the ones used on babys might work as well.

You noted "if no change in RPM proceed in disembling the intake ports for cleaning", can you explain what the intake port is? I will assume it is the hoses that connect to the DPFE (hi and ref) and the EGR nipple.

Also, I was told at Napa that Throdle Body cleaner is good for cleaning the parts and this is much better than brake cleaner (noted in a post I saw).

What are your recommendations?