DPFE Hose & Clogged Cats Problem

[BOOOOST]

Some of you may remember my dilemma, and if not, and you care to read about it, here is the prior thread:

http://www.svtperformance.com/forums/showthread.php?s=&threadid=30345

and

http://www.svtperformance.com/forums/showthread.php?s=&threadid=14547

Basically, what it boils down to is that my DPFE hose keeps blowing off at part throttle and WOT. My car also has a slight surge to it when cold and cruising under part throttle, and when it fully warms up it does not do this anymore. The car is completely factory stock, and has not been modded in any way.

Now on to today...

Okay, well, got my car back from the dealer today and on the way home the check engine light (SES) came on again. Whip it around and back to the dealer, popped the hood, and the same hose is off again. For those of you who aren't aware of what this hose is, it is the DPFE hose, which stands for Differential Pressure Feedback EGR. This hose goes directly down to the metal EGR tube that comes right off the driver's side manifold. This started popping off after about 200 miles on the car, and each time triggers the SES. The dealer ordered a complete new h-pipe, which included all 4 catalytic converters, and today they replaced it. On my service ticket it states:

CUSTOMER STATES THE CHECK ENGINE LIGHT CAME BACK ON. KEEPS
BLOWING THE DPFE HOSE OFF.
QUICK TEST KOEO P111 KOEC P1405. RUN PINPOINT TEST.
ROAD TEST. CK DPFE HOSE. OK. HOOK UP VAC GUAGE TO CK
MANIFOLD PRESSURE ON DPFE HOSE. CALL HOTLINE. TOLD TO
CK CATALYTIC CONVERTER. REPLACE CAT CONVERTER. RETEST
ROAD TEST 20 MILES. CLEAR CODES. RETEST KOER P1111
W? 606 5F250 42 M-TIME SEE RO

So you will know:

P1405 = Differential Pressure Feedback Sensor Upstream Hose Off Or Plugged
P1111 = System Pass

There is a good possibility that my new cats are clogged yet again. I just do not understand this. I have the latest pcm calibration (YDH1) as well. I do know that my car has been running pig rich as well, as I measured the afr via my FJO. I datalogged it to my laptop, and the graph is attached below.

Anyhoo, could it be that the factory pcm calibration is causing the car to run so rich that it is fouling the cats out within 20 miles? I find this quite amazing if so, especially since I stayed mainly around stoich (14.7 afr) after I left the dealer when the SES light came on again (I wasn't measuring, just that I was driving part throttle and cruising, so that is why I'm figuring I was at or close to stoich). Any other ideas or those with similar issues, and if so, what were your resolves?

 

[03DOHC]

Clogged cats was mainly a first run problem. I think you're the second of the new batch of cars to have plugged cats. Not common to the newer run batch.

 

[BOOOOST]

Well, I just spoke to the dealer, and the service manager is calling the Ford hotline to speak directly to them. Hopefully this will be resolved in a timely manner. I really am started to feel sad that my baby is not in my yard

 

[BOOOOST]

My advisor called me today to update me on the status of my mule/snake. They are not quite sure what is wrong, and the Service Manager is actually dealing with the car, as it has everyone puzzled. The Ford tech hotline had him go test the backpressure on the car with the new cats. We're suppose to have 5#'s under WOT stock, and I have 25#'s!!!

Could it be that my new cats are clogged, too!?!? W/in 20 miles of them being replaced?

Any thoughts are appreciated in advance!

 

[CSCOBRA03]

Cats

I am a Ford tech , my guess is that when the cats went bad they may have plugged the mufflers causing the backpressure and the problem. Have them disconnect the exhaust after the cats and retest.It would be a easy test to do and I have seen cats come apart and plug mufflers before. Good luck and let us know what happens

 

[BOOOOST]

Thank you so much for posting that!

You know, I took was considering that earlier, and called my good friend who is a Technician, and Parts Manager of Honda in Pensacola, FL, and he said the exact same thing!

I'm curious to wonder why they haven't figured this out yet? Maybe they have and I'm just not being told everything. I will follow up with my advisor tomorrow with what you all said.

 

[BOOOOST]

Well, I called my advisor and service manager late last night leaving voice messages explaining to them what I thought the problem was. Today they called me to inform me that they were replacing the mufflers :-D

I should have my car back by Tuesday at latest they say, and possibly Monday. Lord I hope so.

Thanks again!

 

[slythetove]

Hope it works out for you.

This forum and the guys / gals on it are so helpful. I love it.

 

[BOOOOST]

Originally posted by BNASPLT
Well, I called my advisor and service manager late last night leaving voice messages explaining to them what I thought the problem was. Today they called me to inform me that they were replacing the mufflers :-D

I should have my car back by Tuesday at latest they say, and possibly Monday. Lord I hope so.

Well, here's the latest, and it's not good, unfortunately.

One of the mufflers was on backorder, so Ford pulled one off the assembly line and shipped it. They JUST got it today, installed both mufflers, and just called me to tell me that the DPFE hose is, yep, STILL blowing off.

My questions were the norm:

Me: "You've replaced all 4 cats, both mufflers, and it's still blowing off?"

Them: "Yes."

Me: "So is there still backpressure buildup?"

Them: "We're not sure at this point, and will not know until next week when we can further test it."

Me: "Could this be something mechanical, but how, if so, because the DPFE hose comes off the driver's side manifold, and I would think that it must be something exhaust related to causing this, or possible a bad DPFE sensor?"

Them: "Well, we hope to find that out soon."

That was pretty much the conversation. I've been nothing but extremely nice, but my patience is wearing thin. I've had possession of this car less than it has been in the shop.

Any further suggestions, please? Thanks in advance for the helpful insight, everyone.

 

[2HORSE CORRAL]

DPFE is clogged or its return line?

 

[magnum4000]

Hate interject with a silly question, but:

I have a first run car - is there a way I can tell if my Cats are clogged? :shrug:

Any advice appreciated.

:burnout:

 

[BOOOOST]

Originally posted by magnum4000
Hate interject with a silly question, but:

I have a first run car - is there a way I can tell if my Cats are clogged? :shrug:

Any advice appreciated.

Do you have any mods currently? From your sig it looks like not really.

What you could do is go run the car real hard at night then pull over and look underneath. If your cats are glowing red hot, then you may have clogged cats.

 

[BOOOOST]

K latest update:

The dealer called me and they have been in talks with a Ford field engineer, and of course the Ford hotline engineers. They have tested another '03 Cobra and it too has the same amount of backpressure on the DPFE hose like mine, yet it is not blowing off on that one. The Ford hotline wants them to put a clamp on it, but the service advisor wanted to wait until he heard from the field engineer before he did that. He said that the field engineer was talking with the maker of the engine to see if that was feasible, and what else they think could be causing that.

I'll let you all know what happens shortly.

 

[BOOOOST]

WOW, I didn't realize that I never updated, so here goes:

Well, after the dealer installed a new set of factory cats, ultimately following that up by changing out both mufflers, the DPFE hose continued to blow off.

Conclusion: Dealership put a clamp on the hose per Ford Engineers. DPFE hose has not blown off anymore, and I haven't received any DTC's in 2.5 months.

I've since replaced the cats with the Magnaflow catted X-pipe as well as the Magnaflow catback. I was going to remove the clamp to see if this would fix the issue, but never have gotten around to doing such.

 

[cobrabull]

mine came off too.it was the rear hose i noticed it
on the dyno and it also burnt the boost bypass vacuum
hose i fixed it and it's still on.my car was built in december
is that a first or second run car????????
thanks tony

 

[BOOOOST]

Originally posted by cobrabull
mine came off too.it was the rear hose i noticed it
on the dyno and it also burnt the boost bypass vacuum
hose i fixed it and it's still on.my car was built in december
is that a first or second run car????????
thanks tony

What pcm calibration code do you have? YDH0 or YDH1? Either is a 2nd run, and especially since you said it was build in December (mind was build in Nov. and has YDH1, the newest calibration).

You noticed this on the dyno you say, but did the light come on to warn you I wonder? I haven't heard of the boost bypass vacuum hose being burnt. Odd.

Also, was this *before* you put on the new catback? I take it you still have the factory cats, 'eh?

 

[cobrabull]

ydh1,no light came on.if the hose pops off at the dpfe
it sticks up toward the blower and directly under the
boost bypass vacuum line that goes to the back of the intake

 

[OCCOBRA]

I had the same problem and burnt the vacuum hose twice. Ford put new cats on and they checked the mufflers and everything was fine. A couple days later i got the code again and i said screw it and clamped it myself on the readings of other people having the same problem. After clamping it the code went away. It is still stock. K&N dynoed the car stock about a month later and it gave 365 hp and Tq so that was not bad for bone stock. My car was built 12/7 with YDH1.

 

[BOOOOST]

Yeah, sounds like we have us two good running motors. I dynoed mine stock and pulled 375.1 and then 363.87 on a backup run just a minute later (damn heat!). With the K&N I pulled 385.78.

Not that it's a big deal, but I wish more would speak up about this DPFE hose problem. I'm sure there's quite a few out there that had the same issue.

 

[SanJoseCobra]

I know this is a really old thread but i am having the same issue. i made sure to buy a warranty thouhh. just picked it up today dealer has so far replaced coils heads and just recently the cats and as i was driving home my car smelled like something was melting i parked got out i could hear my cats crackling and my dpfe hose blew off near the fire wall.