To keep the engine running properly, the powertrain control module (PCM) tries to compensate for the lean condition by injecting more fuel to the mixture in an effort to maintain the proper 14.7:1 ratio. When these adjustments become too large, the Ford P0171 code is triggered.

How do I fix error code P0171?

What repairs can fix the P0171 code?
Replacing the fuel pump.Replacing the fuel filter.Replacing the fuel pressure regulator.Replacing the powertrain control module.Replacing one or more injectors.Replacing one or more oxygen sensors.Replacing the mass air flow sensor.Repairing a vacuum leak.

What causes P0171 and P0174 codes Ford f150?

COMMON CAUSE: A DIRTY MAF SENSOR

One of the most common causes of Ford P0171 and P0174 lean codes is a dirty mass airflow (MAF) sensor. The MAF sensor can also be contaminated by fuel vapors that back up through the intake manifold and throttle body when the engine is shut off.

What causes bank 1 system too lean?

The lean condition can be caused by a vacuum leak, which introduces more air into the air-fuel mixture, or by a weak fuel system, which does not input enough fuel into the air-fuel mixture.

What side is lean Bank 1 on in f150?

Bank 1 is the right side of the truck.