1999 Ford F250 diagnostic codes - "system lean"

1999 FORD F-250
147,000 MILES • V8 • 4WD • AUTOMATIC
Avatar
DUKELOWELL
  • MEMBER
  • 1 POST
I have a 1999 F250 that I've had for a little over a year. Runs great, no complaints. Yesterday my "service engine soon" light came on. Took it in for service and they read the codes (PO171 & PO174) which indicate system lean left bank and system lean right bank. How do I fix this?
Sep 3, 2010 at 6:17 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Advertisement
Avatar
RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Lean fuel condition could be caused by one of the following below:

1.Vacuum leaks
2.EGR and PCV valve.
3.Low fuel pressure.
4.Dirty fuel injectors.
5.Mass Air Flow Sensor.
6.Oxygen Sensor.
Sep 4, 2010 at 2:56 PM
Advertisement