I had the same PVC problem with my Expedition. I was getting the trouble codes P0171 and P0174, but my Expedition needed the heated PVC line. The part number for this, if anyone is interested, is F85Z-6C324-AA. It cost $47. The non-heated one was $28 (F75Z-6C324-JA). I'm surprised they had both in stock.

 

Guys, I'm having the same trouble with my 97, and so far have replaced the PCV, and front O2 Sensor, and it's still shaking when the transmission shifts to a higher gear. I'm now obsessed with getting my truck back to it's original power state. Right now it's pretty gutless, and giving the same two OBD II codes for System Too Lean for both banks. Thanks to everybody here for this "gouge" as I had no idea that there was an additional elbow to look for.

I'll let you know.

Hoss

 

You could have an intake manifold leak. Spray some carb cleaner around and see if the idle changes.

 

Guys, I had the same problem about 3 weeks ago with my '98 Expy. It turned out that the PCV line wasn't the only problem I had. Apparently, the intake gaskets were also leaking around the upper and lower intake. (Black box under the aluminum upper intake). If you have a leak you can't find you may want to look there. The parts ran about $50.00 to fix but plan on spending all day on the weekend to R&R.

Good luck,

Hoseman

 

Well the saga continues. Spent yesterday replacing the intake and Plenum (sp) gaskets, and still idles rough. You can tell it's missing but I'll need to run it and read the codes again.

The last time it was bank one and two...too lean and cylinder 3 & 8 showing misfires.

When I had it in pieces yesterday I cleaned all of the injectors and replaced the coil packs randomly so it it's one of those, it should not show up on 3 & 8.

The only thing left to do is to clean the MAP and hope for the best. I'm out of ideas.

Before the ordel started I noticed the PCV valve "buzzing" so I replaced it. Would this or it's associated vacum line be a factor?

Help if you can!

Hoss

 

After changing the intake gaskets, I ended up changing all the spark plugs due to a situation similar to yours. After changing the plugs and running a tank of gas with Lucas fuel injection cleaner through it, it settled down and no longer has a miss.
I'm going to try running the Lucas through about every other month and hope that keeps thing clear. I've heard it's the best stuff on the market.

Good luck and let me know how things turn out.

Hoseman

 

Try some seafoam through the brake booster line. It'll smoke like crazy for a few minutes but it smoothed out my idle right away. Good stuff.

 

Well I drove it today until the CEL came on.

Checked the codes, and all of them except for the #8 cylinder misfire have went away.

The Intake/Plenum gasket job did the trick on the "Lean Fuel" problem.

Took a stethoscope to the injectors and they are all clicking loudly except for # 8.

I'm replacing it tomorrow and hopefully this will finally put to bed my troubles.

If this doesn't fix the problem, then I have to track the line from the connector to the PCM harness to determine continuity.

Thanks for the additive suggestion. I use Lucas in my F-350 Diesel and it is great.

Haven't heard of "Seafoam", or the straight injection into the brake boost line, but I'm ready to try almost anything.

Any ideas on checking the feed to the injector without one of those specialty parts (Small Light)???

Hoss

 

After I changed the Intake and Plenum gaskets, the "System too Lean" codes went away.

Checked all of the coil Packs with a multimeter and found one of them dead...(It was a brand new jobber replacement - Go figure!) Replaced it and it was stil misfiring on #8.

With the mechanics stetoscope I found one injector not clicking like the others, and another was suspect. Replaced two injectors, and low and behold the darn thing runs like new, with power to spare.

Thanks to eveybody for your suggestions.

Hope this helps somebody.

Cheers

Hoss

 

Hey guys, I'm real new to this, and a real beginner at best when it comes to working on these newer vehicles. I have a '98' Eddie B. 4X4 Expedition with a 5.4 in her, and she's got 81,000 miles. I've got this CEL problem as well. Sounds identical to all these 2003 posts here. Same two codes...bank 1 and bank 2. These codes came up simultaneously just prior to hitting the 80K milestone. I had the O2 sensors replaced this past January. Basically my questions are these:

1- Can someone of limited mechanical ability (namely me) do this himself?

2- How long (mileage wise)can I wait before preforming, or having this job done? Without harming the engine, or having breakdown.

I'm supposed to go on a 600 mile round trip journey with my family and would like to know if I should have any concerns about breakdown. She rough idles, but that's just it...ROUGH AT IDLE ONLY, she runs and performs fine when she stretching her legs locally and on the highway. No noticable power loss, just a huffing and puffing at stop lights, etc... She's not reving high either at idle, holds at about 1000 RPM's.

Any help you folks can give me is greatly appreciated, Thanks in advance!

 

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A minor update on above situation (posting):

Current mileage is actually 80,234, problem CEL started at 79,900+ miles.

Today after previous post, noticed a "hesitation" upon initial takeoff (only happened once, and I'm sure it will only go downhill frm here).

The trip I'm taking is this Friday (7/7/06).

I can't currently afford a mechanic to do the work, that is why I'm curious to see if I can do the job as a total "novice." Or be able to let it go until I can afford a professional. Otherwise I'll need to take out a small loan.

I have found the O2 sensors (front & rear of cat.)

I have located the MAF sensor.

Can't seem to locate the PCV valve, or the hose/elbow/hose leaving the PCV.

To locate this elbow situation is it best to get at from under or over the truck? If I can locate it is there any "quick/temporary" fix I can do for my trip... i.e. Tape job, some kind of sealant? I know that sounds like a cop-out, but if you guys don't think I can do the right job, I need to know if a temporary wrong job will work for now?

 

Same codes on my 98 Navigator. PO171 and 174. So, there's a second elbow? I've replaced the MAF sensor, no help.

 

This Forum saved me money again. I had a rough idle once in a while and then finally the CEL. Codes were PO171 and P0174. Found the leak at the 90degree elbow from the PCV in the back. Replaced it for $4. Back on the Road.

 

If you get both banks lean codes, the most likely thing is a leaky PCV valve hose at the elbow. If its NOT that, and you have tried EVERYTHING else...
The Expedition has a lower intake manifold that is likely made of plastic.
It is fastened to the upper aluminum manifold with a gasket and some bolts.
This plastic manifold tends to crack at the bottom, due to high engine temps (gee, who would have thought). Ford has a corrective aluminum lower manifold that fixes this one for good. The way to test for this is to squirt a LITTLE WD-40 or starting fluid under the manifold. Monitor the engine RPM, and if possible, the upper O2 sensors with a SCAN tool. If there is a manifold leak, the RPM will go up a little (not noticeable if the leak is very small) and the O2 sensor output will swing wildly. If you get a wildly swinging O2 reading, you have a cracked or leaking lower manifold.