P0171, p0174, p0156

[andrewj]

Hey guys,

My CEL came on several days ago so I took it to PepBoys to have them pull the codes. I got following codes: P0171, P0174, P0156.

I know that P0156 code means O2 sensor malfunction (Bank 2, Sensor 2). I read, however, that I should address the other codes before replacing the sensor, if in fact it even needs to be replaced.

So, I suppose a vacuum leak is the first place to look. I have yet to dive in and look for my PCV valve. That'll come tomorrow morning.

Several months ago, I replaced the that 90 degree elbow shown below. The factory elbow had essentially deteriorated into nothing. The section of hose to the left of the elbow had to be replaced as well. I replaced it with some hose I had lying around, the photo below is what it looks like now. Is this hose assembly part of the vacuum system?



Thanks in advance.

 

[andrewj]

I took a brief look at the PCV valve and the line that runs to the intake manifold. I found a small hole in the line just after the PCV valve. I wasn't able to get a view of much else. The line is pretty torqued and creased so I wouldn't be surprised if there were more leaks throughout.

Is this whole assembly (hose line from PCV valve to intake manifold) something I can easily pull out so I can inspect it a little more closely?

Here a pic of the hole I found:

 

[FordandPolaris]

It is fairly easy to remove but be forewarned that the elbow on the back of the intake will most likely disintegrate in your hands. You will want to have a replacement ready for it, costs about 30 bucks from Ford. Pepboys also probably sells a cheap generic replacement. This thread will help you with anything else you might need.

http://www.expeditionforum.com/f27/rough-idle-p0171-p0174-heres-what-you-need-check-first-4926/

 

[andrewj]

So I got the new PCV valve and hose assembly from the dealer. Only set me back $35.

Unfortunately, when I was reaching around the intake to pull off the rubber boot, I bumped my heater hose and broke the plastic connection. It must have been very weak or brittle. So now I have another hose assembly to replace... unless I can figure out a way to use a hose clamp to attach it or something. Below is a pic of the broken part.

Anyway, back to the PCV valve assembly. I am having trouble reattaching the new rubber boot to the back of the intake. Is there some sort of trick that I am overlooking?

 

[rescuer3]

The only tricks I found to help with this were patience, perseverance and luck. I finally managed to reach mine from the drivers side and get enough pressure on it to connect it.