P0174 question

[jjk1224]

Ive read other threads regarding p0171 & p0174 and have done some research on the 00M12 kit (sohc?).
Today, I was helping a buddy move home from his dorm when my engine light kicked on right when I hit the freeway. I had just replaced all my o2 sensors on my 96 4.0L OHV so I figured that might be the problem. Before diagnosing the issue with my scan tool, I helped my friend unload all his stuf and noticed a small puddle of water under my exhaust tip that had an dark, oil like liquid. After I got home, I checked the code... p0174. I proceded to google the code, found similar results, researched and came up with little on my exact problem. First off, the truck does runs like normal and does not show any obvious symptoms and only reads the one code. I recently did an oil change and used 5w30 on accident over my usual 10w30. Temperatures just started getting below freezing where I live in south eastern michigan (rained yesterday and now its 28F... I love MI) and I figured that may be a factor.

Does anyone know what the deal is?
Sorry if im reposting an already answered question.

 

[jremington59]

Go and get some spray and clean the mass air flow sensor and see if that takes care of it.....

 

[ThePhoenix]

upper and lower gaskets solved my stumble and o2 sensors codes. i highly reccomend doing it

 

[manaen]

There are a few things that can cause a lean condition here are the two leading causes
1) vacuum leak (intake or hose) - check for vacuum leaks in all the hoses and seals. You can use an unlit propane torch to test everything, or carb cleaner, but the carb cleaner way, is much more volatile
2) low fuel pressure - run a fuel pressure test if the FPR is running on the low side the pulse width will be messed up and will cause a lean condition
3) MAFS - you can try to clean this if your lucky it may help the problem, but if your lean enough to throw a code I suspect something more serious is wrong (like the first two)

Edit BTW... rarely is the O2 sensor the cause of the problem however it is the sensor used by the computer to report the problem. So don't get caught up by the parts guys trying to sell o2 sensors all the time...

 

[jjk1224]

Well, I did replace my fuel pump last year, and today when I turned my ignition on it sounded like it was squirting fuel everywhere(it was not). I have been running my tank till the check gauge light the past few times before I filled up, but have never "ran out of gas". Im going to check my vacuum hoses and get some cleaner for the MAF tomorrow after work, but the light has not come back on since I cleared the code.

 

[jjk1224]

Well, I just got home and decided to take a look into my MAFS. Before I removed the intake, I noticed a small crack on the MAF housing where it connected to the tubing. Upon further inspection, I realized the inside of the intake tubing and the screen for the MAFS are covered in dust.

Is there A way to properly fix the housing, or does it need to be replaced?

 

[manaen]

someone skilled with plastic welding could probably weld that up. However it would probably easier to use a 2 part epoxy with some fiberglass reinforcement. Just make sure you sand and clean the area very well.

The cleanliness of the screen does not matter. It only serves to remove air turbulence over the maf. The maf itself however does need to be very clean on that model you will need to remove it from the housing to clean it properly.

 

[jjk1224]

How do I take the housing apart? It seems like the inside twists out, but I cant seem to move anything.

 

[manaen]

oh boy, it's been 7 years since I've worked on one of those. But I'm sure someone has the diagram around here...