Check Engine Light (P0171)

[midsouthgeek]

I just posted my 2001 expo on cragslist. Just as I got a call my service engine light came on. Auto zones code finder gave me p0171. They gave me some generic stuff to check. However it runs fine with a smooth idle. Any suggestions?

Thanks Scott

 

[walnuts4x4]

read this

http://expeditionforum.com/showthread.php?t=4926

 

[Big Red Monster]

agree with walnuts, but also i know its a different code but check those hoses coming from the differential feedback sensor right next to the throttle body, mine were both cracked and they came up with a p1405 right after fixing the po174, which is basically the same as a the po171 code