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2005 Ford Focus ZX4 - Code P0171
Posted: Wed Feb 16, 2011 8:40 am
by 805auto
Po171, no vacuum leaks, o2 check ok, baro ok, fuel pressure at 30 psi, pcv system ok, any more ideas?
Re: 2005 focus ZX4
Posted: Wed Feb 16, 2011 8:53 am
by brianp87
What are the fuel trims?
Re: 2005 Ford Focus ZX4 - Code P0171
Posted: Wed Feb 16, 2011 9:43 am
by Tim Martin
Beings it is a Ford, my firs thought would be a Mass Air Flow Sensor out a range. They can be faulty and not set a code.
Re: 2005 Ford Focus ZX4 - Code P0171
Posted: Thu Feb 17, 2011 2:36 am
by steven kiser
since this can be caused by a leak in the crank case look for a bad dip stick as well as a p.c.v. issue. this code has a long list of reasons to trip. you said that the fuel pressure was 30 psi. my specifications call for a minnimum of 35. before i'd replace the pump i'd check the regulator, i'm seeing this mentioned a few times here.
Re: 2005 Ford Focus ZX4 - Code P0171
Posted: Thu Mar 03, 2011 2:00 pm
by Goose
Believe it or not I have seen worn plugs cause this code.