2007 expedition rough crank and P0171/P0174

[Church]

I purchased a 07 expedition and have noticed a few issues.

• I am getting codes P0171 and P0174 every day.
• The engine has very low power
• Horrible fuel economy 10mpg I feel this is low.
• Hard to start. I will sometimes have to turn the ignition off and try to restart before it will crank.

I have changed the fuel filter but looking to see what else the problem could be. I've been seeing a lot about PCV lined but these seem to be on different models.

 

[ExpeditionAndy]

This might help:

 

[Keith92487]

Sounds like a large vacume leak, check for loud hissing around the upper engine, and check all the air intake hoses for a tight fit. Could be a bad/dirty mass air flow sensor. If it runs better unplugged then it's your issue.

 

[Church]

Sounds like a large vacume leak, check for loud hissing around the upper engine, and check all the air intake hoses for a tight fit. Could be a bad/dirty mass air flow sensor. If it runs better unplugged then it's your issue.

I do not hear any hissing in the engine compartment at all. The PCV line is a little rough looking though so I may try changing that.

Doesn't the mass air flow sensor have its own code if it is bad? I will try unplugging it to see if it runs better.

Another thought I had was that the fuel pump might be going out. I have experienced a delay in response when stepping on the gas at times.

 

[ExpeditionAndy]

Church did you watch the video that I posted above? It has good information so you get a complete picture of what is going on.

 

[Bedrck47]

CHURCH

Look at the video that Andy suggested

So as to not repeat myself also check the attached link and look at the information I posted and the link I posted in that thread. The information in that thread may help you.

http://www.expeditionforum.com/threads/p0174.31945/