Gen 4 24V Simultaneous Codes P0171 and P0174 Solution

From Taurus Car Club Maintenance and Modification Wiki

Written by mwt 12/3/07

My car is a 2000 Duratec Vin codes "S".

Another Taurus forum I frequent has been having a lot of these codes lately on 2000 and newer models. A couple of weeks ago I threw the P0171 lean code. I cleared it and ran 5 or 600 miles and then threw P0171 and P0174. This means that both banks are showing lean. Later on, my car started running rough when I started it in the cool morning and it did it every morning thereafter. After doing some research and then acquiring the parts to fix this, it has pretty much been agreed to by other people that have had the same problem.

The problem: The rubber tube that connects from the upper intake manifold and goes down into the PCV valve deteriorates ,gets a hole in it and collapes. This causes a vaccum leak which triggers the lean codes. These are the parts needed to fix the car:

--YF1Z-6A664-AB which is a rubber and steel hose assy available only from Ford. It is about 23 dollars at the dealer and 12 dollars at the online ford places.

--You also need the PCV valve which is Motorcraft part number EV-243/YF1Z-6A666-AA. Please be aware many parts stores have this PCV valve listed wrong.

Some people may be able to fix it differently than I did but the following procedure is they only way I could do it and I am a fairly Decent wrench:

--Take the upper intake manifold off and disconnect all hoses , electrical plugs and fittings off.

--Pull the wiring harness up and out of the way.

--Get a pair of 90 degree needle nose pliers to be able go grab the PCV valve and turn it counter clockwise to get it to come out.

--Put the new PCV in .

--Attached the new hose assy and then put the upper intake on using new gaskets.

This will eliminate the codes and restore a smooth idel and better gas mileage. This is a picture of the correct parts needed for the job:

These parts can be had online for around 20 dollars

Page for reference: http://www.taurusclub.com/forum/index.php?showtopic=51771