Contour Enthusiasts Group Archives Forums General Troubleshooting CEL on;just spent 650 bucks on tune-up &oil change

Is a po401 an ERG insufficent flow code...that is what I get from searching on the boards. Sounds like maybe when they cleaned the engine the ERG got some of the crud from the engine in it. What do you other people think

Okay
This is a little perplexing

P0401
EGR Insufficient flow detected (when by itself, a SIMPLE fix.)

P0402
EGR Excessive flow detected.


Are you absolutely sure that you read the codes/were told codes correctly?

I would think it posible to inverse a two numbers, perhaps an 0420? (Catalyst below efficiency.. caused by major vacuum leaks, which can also cause an 0401. (insifficient because there is a vacuum leak on the EGR.
Actually, I just received that combination of codes (0401/0420) a week ago...

Either way.. IF it is a 0401, 0420, then the things we will check for are:

vacuum leaks (tubes broken, etc)
faulty EGR valve
faulty DPFE (differential pressure feedback for the EGR)
(all DIY if you want to...)

Look in the engine bay and find the EGR valve. (It looks like a little silver UFO disk with a green vacuum tube connected to the top via a small rubber elbow.

Firstly: make sure that green tube isn't cracked, broken, or missing (warning: It will be very brittle, at this age of car, and you could break it if you aren't gentle when removing it from the top nipple of the EGR)

If the tube looks to be in good condition, and the length of tube (running to the back and in to a bundle of red/green tubes) looks great throughout, then do the following:

Remove the green vacuum tube from the top of the EGR. With the car running, apply a vacuum to the EGR nipple itself. (suck on the nipple.. yayaya I know it's the only time I can say suck and nipple on CEG without being rude...)
Does the car stumble and choke/die? (If so, then the EGR itself works great...) (Replace the tube on top of the EGR)

Next we need to check for TINY cracks in the vacuum tubes (so small you can't see them...)

All you do is start the car, and spray carbeurator starter spray in different areas of "vacuum tubes".. if the car stumbles, then the spray made its way in to a small crack in whichever area you sprayed.

If all of this fails, then the more common failure would be the DPFE.. if all those tests fail, then we'll walk you through the way to replace the DPFE.

If the codes are, in fact, 0401, and 0402.. then I can't think of ANYTHING to cause BOTH!!!

Ray

Okay, well.. check the EGR.

Hi Ray!

Thank you for your extensive notes. I am absolutely positive that the lady read the codes right. I was standing right there when she hooked it up. As far as the 'vacuuming' part, can I do this myself? And how and with what? I want to take care of this asap, if you can guide me through it, wonderful. I'll print your notes out today. I may not be able to get to it until tomorrow (Saturday) as I work today. This may be asking way too much, but does anybody here know anyone in the Silver Spring, MD area that I could trust to check this out? A gal I work with recommended Graves Autoshop in Olney and said they were pretty reliable. Who knows...

Kind regards,
Paula

If you are sure they are correct, then you can still test the EGR for proper operation, but I would lean towards a faulty DPFE unit sending signals that are out of range causing excessive and insufficient at the same time (though, they coul have easily happened apart from each other.. not ACTUALLY at the same time)

Like I stated. once you pull that green tube from the top of the EGR, suck on the nipple of the EGR.. (manually. with your mouth if you want!! ) The car should stumble and choke.

From there, test out the "small cracks" by spraying some carb starting spray in the area (careful not to let any spray enter in to the actual air filter, or the car will CERTAINLY stumble, obviously.. You don't want any false positives from that.

Then move on to the DPFE.
Location and removal/prices can be found by utilizing the search feature at the top of every page (next to "my home")
Just search under troubleshooting, and change your date range to "all" and the phrases to "and" (vice "entire phrase".. that would only find a result if it matched exactly...)

Ray

Hi Guys!

Paula here...again:-) Well, I actually decided to give Graeves Autoshop in Olney, Maryland a whirl. They were very nice and didn't charge me to take a look at it. The problem is, all they did was hook the car up to their machine and clear the CEL. They then took it for a spin and the light didn't come back on. I was happy to pick it up, but halfway home DAAAAAAAAAA DAHHHHHHHH!!!! The evil CEL reappeared . So, it's back to the drawing board. What I'm going to do next is all of what Ray suggested. Hopefully, by doing some of those tests, I can figure out the problem. I shall keep you all posted. In the meantime, let's all pray to the great Contour God in the sky. Right now I'm off to watch America's Most Wanted .

Oh, REAL QUICK...if I were to go and buy an EGR valve myself, about how much would that run? And would they have them at ANY auto parts store? Thanks!

Paula

If you WERE going to buy one, most parts stores should carry them... as for pricing:

Autozone's listing is as follows:

Wells EGR - Part# EGR284 $42.99
FELPRO gasket - part# 70149 $1.49

As a member of CEG, I cannot recommend that you EVER purchase parts ANYWHERE without first checking

Signature Lincoln Mercury (CEG members get a discount!) and talking to Bill Jenkins

or

contacting Steve at Tousley Ford (1-800-328-9552, mention his "SVT plan", you don't need an SVT to get the discount.. just merely mentioning the plan nets you about 50% (sometimes more) off..)

Call and price around! The Felpro is a new gasket that you will NEED to replace. (it is REALLY easy to replace the EGR)

Ray

I bet it's not the EGR and it's the DPFE instead. Those POS's fail a LOT on the Duratech.

I think Autozone carries them now too, according to todras. They might list them as an "EGR Flow Sensor" or something to that effect, because if you said "I need a new DPFE" They'd look at you like this: