Why are SES codes po171 & 174 GENERIC codes?
Senior Member
Joined: Oct 2007
Posts: 101
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From: CenCal
Unfortunately, that does not constitute anything remotely resembling a valid test. It takes two consecutive drive cycles in which the test ran and failed to set a MIL.
FWIW, my F150 threw this code combo a couple of weeks ago. I had had it happen late last summer while pulling my boat up 67 from Clearwater, but I never got around to looking into it before the battery died on me. A couple of weeks ago, I was pulling a 4000# trailer of firewood when it came on again. I got the freeze frame data this time and could tell I had a fuel delivery problem as opposed to a vacuum leak problem. I pulled the old fuel filter out this week and could barely blow through it. Popped a new filter on and now the fuel trims all look normal.
FWIW, my F150 threw this code combo a couple of weeks ago. I had had it happen late last summer while pulling my boat up 67 from Clearwater, but I never got around to looking into it before the battery died on me. A couple of weeks ago, I was pulling a 4000# trailer of firewood when it came on again. I got the freeze frame data this time and could tell I had a fuel delivery problem as opposed to a vacuum leak problem. I pulled the old fuel filter out this week and could barely blow through it. Popped a new filter on and now the fuel trims all look normal.
Pretty sure my fuel filter is fine since I changed it out less than a year ago.
What are you using to get the freeze frame data from? A laptop-based OBD II reader?
Senior Member
Joined: Oct 2002
Posts: 7,295
Likes: 125
From: St. Louis (Out in the woods)
Google "Ford OBDII Drive cycle"
I use Alex Peper's setup. www.obd-2.com I've had it for 8 or 9 years now.
I use Alex Peper's setup. www.obd-2.com I've had it for 8 or 9 years now.