2004 Expedition p0171 and p0174 (Pending)
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From: Nevada
2004 Expedition p0171 and p0174 (Pending)
The engine is a 5.4L and is running extremely smooth. I have erased the code and they have only come back once in in a 75 mile stretch and now are still off after 400 mile. My searches have come back to a variety of things, yet I have no substantial symptoms except the codes and maybe slightly elevated MPG.
Any thoughts of where to start?
Any thoughts of where to start?
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Joined: Sep 2010
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From: Southern Cal
The engine is a 5.4L and is running extremely smooth. I have erased the code and they have only come back once in in a 75 mile stretch and now are still off after 400 mile. My searches have come back to a variety of things, yet I have no substantial symptoms except the codes and maybe slightly elevated MPG.
Any thoughts of where to start?
Any thoughts of where to start?
You either need to clean the MAF mass air flow sensor or you have a vacuum leak, probably your pcv elbow over the passenger valve cover.
Very common codes here.
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I just replaced the filter, but with a simple paper one. The MAF could be dirty from the old filter which was DIRTY.
I suspect it's the elbow based on what Ive read on some other sites. One site even gave a part number, but I think he was referring to the 4.6L.
Do they have the same part and location?
I suspect it's the elbow based on what Ive read on some other sites. One site even gave a part number, but I think he was referring to the 4.6L.
Do they have the same part and location?
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From: Southern Cal
I just replaced the filter, but with a simple paper one. The MAF could be dirty from the old filter which was DIRTY.
I suspect it's the elbow based on what Ive read on some other sites. One site even gave a part number, but I think he was referring to the 4.6L.
Do they have the same part and location?
I suspect it's the elbow based on what Ive read on some other sites. One site even gave a part number, but I think he was referring to the 4.6L.
Do they have the same part and location?
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OK, so I located two boots. One coming right out of the passenger manifold that flows to on going into the intake. Both are good, however as I was inspecting the boots I noticed that the PCM valve came out of the manifold very easily with no griping.
Im wondering since its been super cold the grommet in the manifold might have shrunk and in conjunction with its wear caused enough of a leak to throw the codes. I have had a small undetectable vacuum leak for sometime, so do you think my train of thought makes any sense?
I did locate some other small vacuum line couplings that are worn pretty good too, do you know where I can find those couplings...autozone seems to only sell assorted repair kits that seem to only have one that fits.
Im wondering since its been super cold the grommet in the manifold might have shrunk and in conjunction with its wear caused enough of a leak to throw the codes. I have had a small undetectable vacuum leak for sometime, so do you think my train of thought makes any sense?
I did locate some other small vacuum line couplings that are worn pretty good too, do you know where I can find those couplings...autozone seems to only sell assorted repair kits that seem to only have one that fits.
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Im not sure, I bought it only a coupe thousand miles ago. I will plan on doing that no matter what once this cold breaks.
First I will be replacing the PCV Grommet and some vacuum couplings. Ford and their vacuum systems :/
First I will be replacing the PCV Grommet and some vacuum couplings. Ford and their vacuum systems :/
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Postmaster
Joined: Sep 2010
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From: Southern Cal
Right on!
As suggested, just replacing the tee and connections around that pcv system.
As you can see on this forum, it's probably the most asked question. That and COP misfires.
That elbow can look good but still be cracked enough.
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Well, I installed the new grommet and the difference is huge. Fits like a corked bottle of wine now. I had to get a little creative on some of the other coupling replacements due to the lack of good vacuum line repair items on the market, however at this point I have a good feeling about the issue being solved. I will need to drive the truck a bit more to allow for the computer to cycle.
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OK. Update. Light has come back on only this time it is only P0171. Here is what I have done thus far:
Replaced the PCV grommet.
Replaced the Elbow at the PCV Valve
Replaced some random worn small vacuum lines
Cleaned the MAF sensor.
Im thinking the problem is the dredded intake gasket. But I'm hung up on the some of the details.
First do any of you guys know of a detailed "write-up" on replacing this part (Ive yet to find a solid one)? The other thing is what is the exact part name, Ive read intake gasket, valve cover gasket and manifold gasket...which one?
Now Im coming to the gasket due to the fact both codes are not being thrown, now its just the one. Due to the one code I've ruled out the fuel system up to the individual injectors. Ive ruled out a vacuum leak surrounding the PCV since only one code is being thrown. I assume its not an injector because my fuel economy is crappy, so fuel is making it to the engine.
Can anyone help out?
Replaced the PCV grommet.
Replaced the Elbow at the PCV Valve
Replaced some random worn small vacuum lines
Cleaned the MAF sensor.
Im thinking the problem is the dredded intake gasket. But I'm hung up on the some of the details.
First do any of you guys know of a detailed "write-up" on replacing this part (Ive yet to find a solid one)? The other thing is what is the exact part name, Ive read intake gasket, valve cover gasket and manifold gasket...which one?
Now Im coming to the gasket due to the fact both codes are not being thrown, now its just the one. Due to the one code I've ruled out the fuel system up to the individual injectors. Ive ruled out a vacuum leak surrounding the PCV since only one code is being thrown. I assume its not an injector because my fuel economy is crappy, so fuel is making it to the engine.
Can anyone help out?
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From: Southern Cal
The intake gaskets a possibility, but not probable. Too many others things first before digging into that replacement. I also see it pulled both left and right codes originally so may still be an issue tied to both.
Last fuel filter change?
Test fuel line pressure for bad pump?
Exhaust manifold leak?
COP boot cracked and allowing for a "leaky" spark.
Spark plugs changed recently?
Bad O2 sensor? (Not likely).
I still think you might find a vacuum leak under the hood, as this still is the most common issue.
Last fuel filter change?
Test fuel line pressure for bad pump?
Exhaust manifold leak?
COP boot cracked and allowing for a "leaky" spark.
Spark plugs changed recently?
Bad O2 sensor? (Not likely).
I still think you might find a vacuum leak under the hood, as this still is the most common issue.
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Now the fact that the code reader said "pending" on 0174 mean much of anything?
The plugs were changed recently.
Ill check the COP boots.
Now that Im typing this I realize it must almost be surely a vacuum leak because when Im pulling hills and the RPMs go up the hubs start trying to engage...once I move it over to AWD it goes away. Im at a loss in finding this vacuum leak. Ive replaced the elbow at the PCV, tested the elbow at the back of the intake, replaced a line next to the battery, tested the lines running behind the and under the battery & have sprayed MAF sensor cleaner every where.
The plugs were changed recently.
Ill check the COP boots.
Now that Im typing this I realize it must almost be surely a vacuum leak because when Im pulling hills and the RPMs go up the hubs start trying to engage...once I move it over to AWD it goes away. Im at a loss in finding this vacuum leak. Ive replaced the elbow at the PCV, tested the elbow at the back of the intake, replaced a line next to the battery, tested the lines running behind the and under the battery & have sprayed MAF sensor cleaner every where.