| All About OBDII Engine Codes
AutoCodes - Ford - P0171 Ford

P0171 Ford Code - Fuel Injection System Too Lean Bank 1

- Code Popularity: 467,270 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
By - Updated Jul 20, 2022
Share on Facebook   Share on Twitter   Share on Linkedin

|Code P0171 Ford Possible Causes

  • Intake air leaks
  • Faulty front heated oxygen sensor
  • Ignition misfiring
  • Faulty fuel injectors
  • Exhaust gas leaks
  • Incorrect fuel pressure
  • Lack of fuel
  • Faulty Positive Crankcase Ventilation (PCV)
  • Faulty Mass Air Flow (MAF) sensor
  • Incorrect PCV hose connection

|How do I Fix the Code P0171 Ford?

Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Does your Ford have Safety Recalls? → Check here

|Code P0171 Ford Tech Notes

If the P0171 is combined with the P0174 code, the problem is likely caused by an intake leak or the Intake Plenum Gasket and seals. If there are no intake leaks, the next step is to replace the air filter and clean the airflow meter. If the problem persists, the front oxygen (O2) sensor may need to be replaced.

Link to a website with information on how to replace the Intake Plenum Gasket and seals:
1999-2003 Fords Windstar Code P0171

There is Factory Service Bulletin for the following Ford Models:
2009-2010 Ford F-150
2009-2011 Ford E-150
2009-2011 Ford E-250
2009-2011 Ford E-350
2009-2011 Ford E-450
2009-2011 Ford Expedition
2011 Ford F-250
2011 Ford F-35
Ford Factory Service Bulletin OBDII Code P0171

2004 FORD F150 P0171, P0174, P0301, Misfire, and Lean Condition

User Submitted Video

|What is the Cost to Diagnose the Code P0171 Ford?

Labor: 1.0

The cost of diagnosing the P0171 Ford code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

|When is the Code P0171 Ford Detected?

- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too small. (The mixture ratio is too lean.)

|What are Code P0171 Ford Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Excessive Fuel Consumption

|Code P0171 Ford Description

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the Malfunction Indicator Light (MIL) (2 trip detection logic).

OBDII Code P0171 Ford - Fuel Injection System Too Lean Bank 1 -
P0171 Ford Code - Fuel Injection System Too Lean Bank 1

|Need More Information on the P0171 Ford Code?

Need more information on how to fix the P0171 Ford code? Get Access to Factory Service Manuals

|Need Help with the P0171 Ford Code?

Get the P0171 Ford code diagnosed by a professional: Find a repair shop in your area

|Code P0171 Ford comments

Help us improve Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the P0171 Ford code? Have you replaced any parts?
Any information is appreciated. Thanks