egr code ruff idle need help please

[undead123]

I have a 96 ford explorer with egr code showing up ruff idle stalls out at idle Ive replaced the hole entire egr its self and pipe still nothing im getting a bigg hint into my mind i have a intake leak but will that cause egr to show? i here wrestling i spray anything i can find around intake no idle picks up i can unplock the break boaster hose and nothing changes in idle i have alot of time under a hood but i cant figure this out i have a feeling i have a intake problem but thats the only code showing up but do you think its lower or upper gasket? or if im in the wrong direction please help me im suckin gas like crazy and tired of two footing at stop lights

 

[jremington59]

The Idle Air Control valve is most likely your stalling problem. The egr problem could be the dpfe sensor or other things. The idle problem is the easy fix.

 

[undead123]

yeah i get that but what im thinkin is that i may have a intake leak with is causing the bad idle and not even suction on my vacume lines to my egr because both problems came at the same time but i could be wroung reason for me askin lol but just give me some pointer guys im in need bad

 

[Chikar]

Can you tell us what the actual EGR code is?

If you can pull the hose from the brake booster and nothing changes you must have a major leak somewhere.

Possibly in the brake booster itself?

 

[undead123]

its a p0401 ive change the egr twice nothing and i know i have a bigg leak i wasnt thinkin that at first just changed egrs and now its still the same so i tested for leaks ive sprayed everywhere with starter fluid everything no idel picks up may not be spraying in the right place thou

 

[Chikar]

You might want to read through this posted by a mechanic with 16 years experience.

http://www.justanswer.com/ford/2o6n5-p0401-code-1996-explorer-4-0-liter.html

The problem may be the DPFE. Hopefully the tests will point you in the right direction.

 

[jremington59]

You're not going to have suction to the egr at idle. The egr doesn't open at idle. It opens when the sensor tells it to while you're driving. If you want to know if the egr valve is good, suck on it with light suction while it idles. If the engine stumbles, then it's not the valve itself. I have no clue why you'd change it twice. The only way the egr would make it stall is if the valve were staying open.

It's most likely your Idle Air Control valve.

 

[gonenuke]

How are your EGR gaskets? The flat metal one on the valve, and the plastic one going into the intake.

 

[undead123]

well i went and got both sensors still doing the same thing and yes i have the gasket on and i changed it twice cause first one was a junk yard one 2nd brand new soo any one have any ideas?? im assumeing intake leak but befor that any other ideas?

 

[budwich]

Its unlikely you have a air leak.... IF you did, you would likely have related codes. As people keep telling you, pay some attention to your IAC (clean, replace, whatever).

 

[Chikar]

"The most common issue is the failure of the EGR Pressure Feedback sensor commonly known as the DPFE sensor. If the diaphragm in the sensor becomes weak or the sensor is contaminated with moisture it can fail to supply the computer with the correct reference voltage. When this occurs, the computer increases the vacuum supply to the EGR valve causing the vehicle to run poorly. When the low flow signal is unable to be corrected by the computer’s adjustment, then the computer sets a P0401 code for EGR flow."

Above is an operational explanation on-line. This page http://www.bwdbrand.com/BWD - Just The Facts-Don't Get PO'ed with PO401 Codes/Content.aspx gives the complete write-up as well as a helpful diagram showing how the system works.

So a couple of things.

I think you should be taking a close look at the DPFE and it's surroundings. If it's pulling the EGR valve open, particularly at idle, the truck is not going to run well.

But what still has me wondering is why you didn't see at least some change in idle when you disconnected the hose to the brake booster. That would be a huge vacuum leak and you should have seen an engine idle change.

 

[Chikar]

I just noticed your post about getting both sensors. Which sensors did you get?

 

[jremington59]

As budwich stated, a vac leak of that magnitude would throw one, if not multiple codes.

I guess if you want to keep speculating it's a vac leak, then it's your rig, but if it were me the first thing I'd suspect is the IAC valve. We've all had one or two go and it's best to eliminate that from the equation first. I'd also get a meter and check the DPFE and see if that's working correctly.