P0171 and P0174 error codes on 2004 Expedition XLT 4WD
 

Hi, I have a check engine light on causing my suv to have jumpy throttle and stalling issues when the gear is in drive. I have a Ford Expedition XLT 4WD 2004 4.6L engine. I have gone to Auto Zone where they checked the codes and told me that it was an error associated with an O2 sensor. Was not sure, so I went online to investigate it. Found these things:

1. Clean the MAF(Mass Air Filter) with electronic cleaner. (Heavily Spray the MAF).
2. Wait to dry and do it again....... Install MAF
3. Issues with fuel injectors (being dirty).
4. DPFE issue being faulty........ Or a EGR faulty.........

I'm not a mechanic by all means but can change brakes and small jobs like that. Just wondering if anyone can give me some advice as to where I should start. Step one seems like the idea but I have already tried that. Did not work. Fuel injectors too, not work. Need some advice. Thanks so much for taking the time to read this.

The problem is due to a cracked $11 rubber elbow at the rear of the intake. You can usually find it at an auto parts store in the red package HELP section part #46017.

Here's one of my posts that has a picture of the PCV sytem. The elbow is in the red circle.
https://www.ford-trucks.com/forums/1...l#post10502496

Thanks for the advice and the picture that shows the location. Will let you know how it goes.

Could Not locate the Elbow. Similar Found
 

Found something similar, (elbow piece connecting to some other hoses) but it appeared to be ok. Not cracked at all and looked ok. This guy at Lincoln Mercury told me that it may be a faulty DPFE sensor. So, I replaced that. It did not resolve the issue. How much will Ford charge to do a diagnostic on the vehicle? I had asked him but it appears he does not sound like he knows or he is not sure of himself anymore. I have already paid 70.00 dollars for the sensor at employee discount. I went to Auto Zone to get the read outs again and these came up. P2197 Heated O2 sensor Bank 2 Sensor 1, P2195 Heated O2 Sensor Bank 1 Sensor 1, Along with P0171 and P0174. Second question, will a Ford mechanic know which sensor is faulty and replace that one or two; or will he just say the whole unit is bad and charge me some 500.00 to 1000.00 for the fix. I am guessing that the diagnostic charge will be something like 100.00 dollars or so. But who knows??????? Need some advice as to what to do next. Thanks for reading.

LastKahuna007:-huh

Everything about those 4 codes you're getting screams vacuum leak. Look again.

Sorry, I will check again. Thanks So much for your time though. I will let you know the status.

Helpful tip to finding vacuum leaks:
Take wd-40, spray all along every vacuum line. When you hear the engine rev up, then you know you have found it.

WD-40 sounds messy, why not use carb cleaner instead?

That part is for a '97-'98.
I don't think our 2003 or LastKahuna007's 2004 has an elbow like that.

It's Fixxed Finally..... THANKS......
 

It was a hose that was leaking. I could not locate it immediately due to other hoses that were atop of it. If you're looking at the engine from the passenger side of the car it was located under the 4 connector hoses. I got the hose from Ford it was part number 2L1Z6758GA and it was called a tube assembly PCV. I replaced the hose. It actually took me awhile to replace it due to my inexperience but I got it done. Thanks to everyone here. I really appreciate it.:D

Works as well.. Sometimes you only use what you have at hand, and that was the only thing I remembered ever using on that kind of problem!