P0401 EGR Insuffucient Flow + Mutation ? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Troy B · 05-27-2008, 19:58

2001 Mercury Sable DOHC S-serial V6

Hello all.

My wife's car threw a 401 the other day and I began surfing the web for intel. I found plenty of it - Especially here - TY !

The 401 still exsists, after pulling the UIM (Upper Intake Manifold) and cleaning everything about it (see note below) and re-installing everything as if I were never there (see new issue below). I replaced the UIM gaskets, air filter and sparks while "there" as well.

Note: I have read the (included) links below and many, many more posts, blogs, and sources of information as well.

Quote:

Originally Posted by RickMN

Read these two articles

P0401

Understanding DPFE

While the UIM was off, I looked over it completely. I also looked very closely at the seperated throttle body. I did not recognize any ports - Or what I would consider a port anyway - Which could be or which were clogged of carbon build-up such as that mentioned in the articles. This left me wondering if perhaps the three ports were changed by design in later models being that it was discovered as an issue (?). I did see a "half moon" area on the throttle body but it contained one large through port.

Regardless, I cleaned everything with pipe cleaners and solvent before re-assembly. I didnt even see a place to scrape with a screwdriver (to remove the carbon build-up) as suggested somewhere while reading input. At this point, I am seriously considering replacing the sending unit.

Is there any further insight which may drop the 401 ? I am willing to tear everything down again without hesitation so "fire away". I'd especially appreciate further detail of the mentioned (clogged) ports by size or some other easily recognizable feature.

New issue: Today, during the same call which informed me of the 401 re-surfacing, I was also told that...............drum roll..............The A/C is blowing nothing but hot air - The vent alone is blowing nothing but hot air - And the windshield defrost .......HOT AIR ! Wonderful. Considering, to my knowledge, I didnt even touch anything related to the A/C or venting system while tearing down for the carbon build-up removal, this one has me completely baffled.

I am wondering if by having the battery disconnected over night (While waiting for the UIM gaskets to be transferred to my local Autozone), could it have effected something with the computer based climate control which needs resetting. Or is there a possibility of the heater only somehow being engaged no matter the selection - By a missing connection (of my own doing). I have confirmed that everything is proper with the A/C system (Compressor responds, freon is strangely dead center for proper level of charge, etc), and even gone as far as to double check all connections regarding the UIM tear down.

Im popping a flare on this one - Im lost. Any help with this issue or direction pointing would be immensely appreciated being that Im getting the evil eye from the wife at this point

.

Thanks for the response in advance

Troy B
Ft Hood TX

SHOZ123 · 05-28-2008, 09:30

The EGR port that gets clogged is usually on the intake manifold. It is where the EGR valve actually attaches to the manifold.

Troy B · 05-28-2008, 15:11

Thanks for the reply SHOZ123.

I know the passage you're referring to. I'm going to remove the throttle body again, the EGR valve mount and give it another go.

My confusion comes from the quote below, found in the first link "P0401"

Remove the throttle body and gasket. Behind the gasket you will find a half moon shaped passage with 3 openings into the intake manifold. Most likely you will discover that the passages are clogged with carbon buildup. Clean out the passages with a small pick and some throttle body cleaner.

I guess while the throttle body is off, I'll re-check all electrical connections again. The A/C issue is slightly more pressing due to high 90's for daily temperatures - The wife keeps reiterating how uncomfortable her driving has become and the only end to this reminder is (obviously) the fix which eludes me.

Thanks again for the reply !

Troy B
Ft Hood TX

UPDATE

I started this evening by erasing the code. I then took everything apart again. I went further and removed the EGR passage/port from the UIM and gave it a thorough cleaning - It was the only part which I saw as needing any further attention. I wiped everything once more and re-assembled the UIM and everything attached to it. I wont know more until tomorrow once the Sable is driven.

The strange issue with the A/C, vent, defrost blowing nothing but hot air - It vanished. The A/C is now operating as designed. Im still curious as to what caused the issue to occur. When re-assemblng the UIM (etc), I only hand checked every connection I noticed - Hardly what I would consider finding the cause.

I will post again once I have more information.

RickMN · 05-30-2008, 17:36

Troy,

Try this link and download the PDF. Go to page 28. It explains the theory. Ford 2001 OBDII

Troy B · 05-30-2008, 20:29

Thanks for the response, Rick.

The code still exsists.

I've printed many an article and also have the Chilton manual on hand.

At this point, I'm going to bypass further physical troubleshooting and pick up a DPFE sensor for super cheap. In the past I have picked up many parts to include a flawless BMW PCM for 20 bucks, which books around 189.00 if I recall correctly - The vehicle had been totaled by a rear end collision. This yard is crazy-in-expensive with a 2 dollar entry fee. I'll get the DPFE and pay at most 2-3 bucks for it.

Some may frown upon this decision - But it is harmless to play trial and error with a few dollars. If it clears the 401, good deal - If it doesnt, then there's a few bucks lost instead of 30 for the DPFE or 60 for the EGR valve.

I'll post an update as soon as it occurs.

Thanks for the help !

Troy B
Ft Hood TX

**tbird100636** · 05-31-2008, 11:23

Quote:

Originally Posted by Troy B

Thanks for the response, Rick.

The code still exsists.

I've printed many an article and also have the Chilton manual on hand.

At this point, I'm going to bypass further physical troubleshooting and pick up a DPFE sensor for super cheap. In the past I have picked up many parts to include a flawless BMW PCM for 20 bucks, which books around 189.00 if I recall correctly - The vehicle had been totaled by a rear end collision. This yard is crazy-in-expensive with a 2 dollar entry fee. I'll get the DPFE and pay at most 2-3 bucks for it.

Some may frown upon this decision - But it is harmless to play trial and error with a few dollars. If it clears the 401, good deal - If it doesnt, then there's a few bucks lost instead of 30 for the DPFE or 60 for the EGR valve.

I'll post an update as soon as it occurs.

Thanks for the help !

Troy B
Ft Hood TX

Well $30 new is cheaper than the $70 I spent 3 years ago at AutoZone.
As far as your A/C Problem do you have EATC or Manual controls???

Troy B · 05-31-2008, 19:41

The system is EATC (Electronic Automatic Temperature Control) - Set it to the desired temperature and drive. Which is why I was asking if, perhaps, something needed re-programming after having the battery disconnected over night.

I doubt thats actually what happened being that after I tore down the UIM the second time, and re-assembled everything once again - The A/C worked (and still works) as designed. It brings a bit of curiousity to mind of "why" it happened though.

Im open to ideas and/or possible explanations though, of course.

Your questioning the costs of each component leaves me wondering what part the sales clerk actually looked up (It was a phone call senario). I may go in person tomorrow simply to verify. It was 30/60.00 for the DPFE/EGR valve. Hmm.

Thanks for the response !

Troy B
Ft Hood Texas

**tbird100636** · 05-31-2008, 22:11

Quote:

Originally Posted by Troy B

The system is EATC (Electronic Automatic Temperature Control) - Set it to the desired temperature and drive. Which is why I was asking if, perhaps, something needed re-programming after having the battery disconnected over night.

I doubt thats actually what happened being that after I tore down the UIM the second time, and re-assembled everything once again - The A/C worked (and still works) as designed. It brings a bit of curiousity to mind of "why" it happened though.

Im open to ideas and/or possible explanations though, of course.

Your questioning the costs of each component leaves me wondering what part the sales clerk actually looked up (It was a phone call senario). I may go in person tomorrow simply to verify. It was 30/60.00 for the DPFE/EGR valve. Hmm.

Thanks for the response !

Troy B
Ft Hood Texas

Other people have come on here recently stating they payed $30 for the DPFE Sensor. For your EATC, sounds like the problem I had. It was the temperature blend door actuator (motor). If I had it set for 72 degrees or over then shut it off set at those temps. The actuator would lock-up and when I tried to lower the temp. it would not change. I would put it into diagnostic mode and it would clear up. Remove the ICP (Radio/EATC panel) and youwill see it on the A/C box.

Troy B · 06-07-2008, 19:46

Installed a <new> DPFE today - $28.00.

Broke an UIM bolt too

Bolt is already cleanly extracted - Heading back to the Pick-n-Pull yard tomorrow for some intake boltage - Auto part stores seem to think the "HELP" isle can ......help - lol.

Hopefully, the issue is resolved.

Havent had the AC issue re-surface to this point.

Troy B
Ft Hood TX

**tbird100636** · 06-07-2008, 20:18

Quote:

Originally Posted by Troy B

Installed a <new> DPFE today - $28.00.

Broke an UIM bolt too

Bolt is already cleanly extracted - Heading back to the Pick-n-Pull yard tomorrow for some intake boltage - Auto part stores seem to think the "HELP" isle can ......help - lol.

Hopefully, the issue is resolved.

Havent had the AC issue re-surface to this point.

Troy B
Ft Hood TX

Just keep your EATC set to 60 or below 70 before shutting it off and you should be fine.