P0171 code System Too Lean (Bank 1) Subaru Forester SH5 Turbo

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) A faulty mass air flow sensor What are the symptoms of the P0171 code? Symptoms of the P0171 code may include: Loss of power Check Engine Light Hesitation or stumble from the engine Engine may be difficult to start Engine may die Catalytic converter damage may result if this code is stored for a long period of time