P0171 2008 FORD FUSION - System Too Lean Bank 1
Intake air leaks
Faulty front heated oxygen sensor
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Air Flow (MAF) sensor
Incorrect Positive Crankcase Ventilation (PCV) hose connection
If the P0171 is combined with the P0174 code, it's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replace the air filter and clean the air flow meter. If the problem persists the front oxygen (O2) sensor may need to be replaced.
When is the code detected?
- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too small. (The mixture ratio is too lean.)
Engine Light ON (or Service Engine Soon Warning Light)
Excessive Fuel Consumption
P0171 2008 Ford Fusion Description
The adaptive fuel strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit.