Ford Expedition P2195 P2196 P0171 P0174 Codes

IT finally happened, the 2004 (I thought it was a 2003 go figure) threw on the Check Engine Light (well LED actually) and I came to the rescue with the Snap On MTG2500 that I picked up on eBay. I also got extra fancy and hooked up the battery powered thermal printer to dump the codes.

The symptoms were the car was running oddly rough at idle, and it started to shake, but would drive just fine. After pulling the codes it seems this is a common DTC to cars of this era. Some are related to intake manifold, some are to the vacuum line system, most the one connected to the PCV Valve. Both are causing a vacuum leak that is messing with the idle. I hope that it is not an intake manifold as I would NOT like to do that work or have to write up that story...

So I popped the hood and fired up the engine. It was running rough still. I could hear the vacuum leak so it was a bad one. Would be just a bit of work to find it in the maze of hoses and tubes that are on the engine.  After finding it it seems that I fixed it with a short piece (maybe 2") of 3/8" Fuel line.  The cost is about nothing if you have a piece of scrap laying around. Do this diagnostic work before taking it into the Ford $teelership or you will be sorry...
Expedition P2195 P2197 P0171 P0174
Snap On MTG2500 Pulling the Error Codes
Diagnostic Codes Expedition P2195 P2197 P0171 P0174
Expedition Cracked Vacuum Line
Expedition's Engine Bay

Pulling the Error Codes with the Snap On MTG2500

I have finally got to use the old MTG2500 Engine Diagnostic Scanner. I'm happy for that. Hopefully it will tell me what's really going on. I have a nice battery printer that plugs right into the scanner so I can print out most any information, but mainly the DTC (error codes) that will let me find out what's going on. Most any scanner would also do the job. If you need a low cost Engine Scanner and have a Cell Phone (Andrioid or Apple) take a look at some of the low cost options that use wireless and your phone to scan and reset codes. They are in the $20 range. Just make sure you get the right one as they are Apple and Android specific. I tend not to want to use my phone for that stuff, but they are cool and very inexpensive. Even a good quality scanner is about 60 bucks and worth every penny if you have to use it and it save you from going to the $tealership.

Expedition Engine Compartment

Popping the hood on the Expedition and this is what you see. Not a place I want to spend any time working on I can say that. However it's not as bad as it looks. Most of the vacuum lines are under the engine cover. It's the black thing with the FORD emblem and to bolts just visible on the side of it. You will need to remove this cover to get to most of the problem areas. Note that this is a 5.6L V8. I would imagine other years/engine combo's are similar.

The Expedition's Error Codes

Easy to see and nice to have a print out of the codes. The P2195 and P2197 are just Left and Right O2 Sensors indicating a lean condition that can't be corrected. The P0171 and P0174 more general error indicating the same thing. Not to have the description of what the PXXXX error code is so I didn't have to look them up.
GTSparkplugs Header
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Expedition's Engine Cover

Expedition Engine Cover

Remove these two bolts (they are metric) and just pop the cover up. It's help on the opposite side by a couple of snaps that pop off with a pull up once the bolts are removed.

Cracked Vacuum Line to Throttle Body

On the passenger side of the throttle body a plastic line connects to a rubber boot to the throttle body. This was the problem. The hose was cracked almost all the way through and had a pretty good sized gap. This was the root of the problems. You could hear this one with the engine running. The cracked hose (or is it a coupler?) was easy to remove. The tube on both ends looked at first like 5/16" host and I forced a piece on but was just to tight to slip over the plastic side of the tubing. So hoping that 3/8" would not be too loose, and it wasn't. A short piece of 3/8" hose pushed on with enough force and to not require any sort of clamps. If you have a different model I would suggest looking in your valve cover for the PCV valve and then follow all lines that it connects up to. Most of the vacuum lines seem to be made out of plastic with elbow couplings or straight couplers holding things together. Water in a spray bottle can also be used to find cracked hoses just listen for the idle change.
Expedition Cracked Vacuum Coupling

Cracked Vacuum Coupling

This is the fitting. It seems that just vibrations ultimately cracked it. The rubber was still good except for the cracked part. If you look around on the web you will see many different parts that have either cracked or melted due to high under hood temperatures. It's a good idea to inspect the entire set of lines that for cracks and melted fittings. If you need to replace more then some of the 'couplers' you likely should just get the entire new assembly. For my vehicle a 2004 Ford Expedition it seems to be this part number (PLEASE DOUBLE CHECK FOR YOUR SPECIFIC VEHICLE!!)


Ford Expedition Vacuum Line Fix - Wrap Up

I think I got lucky on this one. For now just the one hose was cracked. I would expect in a vehicle that's now 10 years old a few things like this to start hapenning. I will expect the more common melted fittings to also show up at some point so if the engine starts throwing DTC codes again that will be the first thing I will check. Again INSPECT the entire set of lines, some of them are hard to see but you can feel them with your finger to see if they are cracked or melted.