Causes of the P0171 code may include: A faulty fuel pressure regulator. A weak fuel pump. A clogged fuel filter. A faulty powertrain control module. A vacuum leak. Faulty injector(s) Faulty oxygen sensor(s)

What does code p0171 mean?

The P0171 code means that, on the first bank of the engine, the fuel system is running weak or a vacuum leak exists near this side of the engine. A lean condition occurs when the engine either receives too little fuel or too much air.

What is a p0171 code?

A Ford P0171 is a LEAN code fpr cylinder bank 1, and P0174 is a LEAN code for cylinder bank 2. These codes commonly occur on many Ford vehicles, and are set when the powertrain control module (PCM) sees the air/fuel mixture is running too lean (too much air, not enough fuel).