P171 Code
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Junior User
Joined: May 2004
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From: Chicago, Illinois
P171 Code
My 1999 Ford Expedition is throwing code P0171. This is a lean condition so I checked the PVC hose & valve & all other hoses & found no leaks. I also sprayed the MAF sensor. Any suggestion regarding what to do next?
Thanks in advance!
Thanks in advance!
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Ford p0171 AND p0174 codes
Ford p0171 AND p0174 lean codes can also be set by a bad EGR differential pressure sensor. Check your EGR valve and DPFE sensor. High failure rate on DPFE sensors on high mileage Expys. Be sure to buy the Ford brand DPFE sensor if needed, NOT off brand.
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Junior User
Joined: May 2004
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From: Chicago, Illinois
P171
I understand that, but if the DPFE was bad, wouldn't I get code P0141 instead of P171? Can a bad DPFE cause a lean condition?
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Bad DPFE sensor can under report EGR flow, resulting in lean condition. Google your trouble code to research further.
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Joined: Feb 2003
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From: Long Island, NY
I recently had the same types of issues, and I was getting both the error codes as you mentioned. I know you said you checked the PVC valve and line, I did as well but I decided to get the following part # F85Z-6C324-AA anyway. I think it was around $35 bucks. It worked like a charm and pretty easy to install. Here's a good site the describes what most likely is happening to yours as well. 1998 Ford Expedition Vacuum Assembly. Good Luck and hope it works!
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Thread Starter
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Junior User
Joined: May 2004
Posts: 70
Likes: 0
From: Chicago, Illinois
P171
I recently had the same types of issues, and I was getting both the error codes as you mentioned. I know you said you checked the PVC valve and line, I did as well but I decided to get the following part # F85Z-6C324-AA anyway. I think it was around $35 bucks. It worked like a charm and pretty easy to install. Here's a good site the describes what most likely is happening to yours as well. 1998 Ford Expedition Vacuum Assembly. Good Luck and hope it works!
Postmaster
Joined: Jan 2009
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From: Chesapeake, Va.
Before you do all that work, try reversing the small vacuum type hoses that come off the big egr pipe to the sensor. I had a similar problem with my Navigator and found that I had the hoses on backwards. It's an easy mistake to make as they seem to be the same size.
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Junior User
Joined: May 2004
Posts: 70
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From: Chicago, Illinois
P171
Thanks!
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1998, 1999, 6c324, 99, code, dpfe, expedition, f250, f85z, f85z6c324aa, ford, motorcraft, p0171, p171, trouble
