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-   4.0 SOHC / 4.0 OHV Tech (http://www.fordrangerforum.com/4-0-sohc-4-0-ohv-tech/)
-   -   The Infamous P0171 and P0174 codes troubleshooting (http://www.fordrangerforum.com/4-0-sohc-4-0-ohv-tech/27034-infamous-p0171-p0174-codes-troubleshooting.html)

Lee_T413 02-19-2011 07:12 PM

The Infamous P0171 and P0174 codes troubleshooting
 
alright, lately i have been experiencing this issue, i have taken out the MAF sensor, cleaned it with MAF Cleaner and also even tried replacing the MAF. The same codes show up. i have done a quick scan of some hoses and cant seem to find anything, there are no noises either. What are some problematic areas for the 2000 4.0l and if anyone else was experiencing this problem please share thanks.

FX4OR 02-19-2011 07:22 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
there is THIS sticky in the 4.0 section, not sure if the same applies to your ohv engine, though... I'd still have a good look at all the connections between the hoses and what not under the hood.

southbama man 02-19-2011 07:26 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
Had the same problem for months. I changed the MAF sensor twice (No, I didn't pay for two of them. One was a return) , changed 02 sensors, changed air filter frequently (like that was causin it lol), and changed out rotten vaccum hoses. Only to find out that it was my pcv valve and I had to go buy the whole pcv valve kit.

Lee_T413 02-19-2011 07:48 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
haha wow, maybe that should be where i check next. Where exactly is the pcv valve? and i've already checked the sticky and its not the same as mine

southbama man 02-19-2011 07:58 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
Driver side of the manifold on the back. I'll try and post a pic.

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Here you go. If it doesn't look like this get back on here and let me know. http://i2.photobucket.com/albums/y28/OneBad93/pcv.jpg

FX4OR 02-19-2011 08:10 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
yeah, the sticky (and those codes) are related to the pcv system, so it's very possible that the valve is bad, even given the different setup. If its still throwing codes after a new valve, or if the valve checks out ok, check all the hoses related to the pcv system, and their connectors for cracks/tears, etc.

Lee_T413 02-19-2011 08:10 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
i have found it, thanks. I could pull it out fairly easily is this ok? i had also looked at the tubing and it seemed fine.

mutt300 06-20-2014 11:13 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
can someone show me where it is in this picture?


http://i283.photobucket.com/albums/k...17/unnamed.jpg


Quote:

Originally Posted by southbama man (Post 331672)
Driver side of the manifold on the back. I'll try and post a pic.

----------

Here you go. If it doesn't look like this get back on here and let me know. http://i2.photobucket.com/albums/y28/OneBad93/pcv.jpg


Jswifto 06-21-2014 04:15 AM

I had the same codes on my 99 4.0 and I replaced the upper plenum gasket and retorqued the lower intake bolts ... They were only hand tight. It fixed my problem with the lean codes.

Robramrod 06-22-2014 05:52 PM

Vacuum clamp all vacuum lines and see if that helps 5\16 clamps fit just right they can be purchased from the hardware store.

Robramrod 06-22-2014 10:07 PM

Also make sure all additional vapor lines are clamped and free from cracks and holes, for example evaporative emissions lines, positive crankcase ventilation lines, and make sure the air intake manifold T 30 bolts are torqued to the correct specifications 89 in lbs is what the Haynes manual gives.

Robramrod 07-22-2014 05:27 PM

It also helped to count rpms starting at the top going down until I could settle on the correct rpm range. Intake air temperature may come into play here too. The air box mod if it was done to your vehicle will trigger this code. So try not to change the intake air temperature with fresh air it may create enough of a change to trigger the check engine light

Kanook 11-19-2014 04:21 PM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
Quote:

Originally Posted by Robramrod (Post 2204966)
It also helped to count rpms starting at the top going down until I could settle on the correct rpm range. Intake air temperature may come into play here too. The air box mod if it was done to your vehicle will trigger this code. So try not to change the intake air temperature with fresh air it may create enough of a change to trigger the check engine light

Hello, new here and have been lurking for a bit. I'm dealing with these codes right now. I need to get them cleared up so I can get my inspection done. I've also got the p1443 but that's a different topic. So far I've check for vacuum leaks with ether. Cleaned the mas and throttle body. Today I did the fuel filter which was nasty inside. Fingers crossed. But reading the previous post got me thinking. My truck has an aftermarket K&N filter and the stock air box has been removed. Could this be the issue? Any thoughts? Thanks

Jswifto 11-19-2014 07:31 PM

First of all you need a sig so we are know what you have. Second have you looked at the stickies on the lean codes? Those would be very helpful if you read thru it.

Kanook 11-20-2014 01:42 AM

Re: The Infamous P0171 and P0174 codes troubleshooting
 
Quote:

Originally Posted by Jswifto (Post 2312056)
First of all you need a sig so we are know what you have. Second have you looked at the stickies on the lean codes? Those would be very helpful if you read thru it.


I'll add that. I have a 97 2wd 4.0.


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