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code po171 in a ford focus

Vehicle: 2006 ford focus 4cyl.
asked Sep 20, 2012 by anonymous

2 Answers

This indicates a lean fuel mixture. Normally caused by a leak in the vacuum line to the pcv valve. This can also be caused by low fuel pressure and a faulty mass air flow sensor. If you don't find a vacuum leak, then it's best to be properly diagnosed with a scan tool
answered Oct 27, 2012 by milonajo1 (737 points)
I had this error and finally found the problem. The PCV valve hose was split. This is located under the intake manifold. It took about 45 minutes to take the intake off so I could get to the hose. I replaced it and it took me less than 30 minutes to reinstall everything. The code went away and the car is running great.
answered Jul 26, 2013 by Tim

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