P0171 Code - System Too Lean Bank 1

Discussion in 'P - Powetrain Codes' started by fault code, Dec 11, 2017.

Tags:
  1. fault code

    fault code Administrator Staff Member

    Joined:
    May 11, 2017
    Messages:
    1,023
    Likes Received:
    0
    Trophy Points:
    36
    What Does P0171 Mean?

    Combustion engines function best when they maintain a specific ratio of air to fuel (about 14.7 parts air to 1 part fuel) in the fuel mixture. To keep the engine running properly, the engine control module measures the oxygen content in the exhaust with oxygen sensors and makes adjustments to the mixture by injecting more or less fuel as necessary. When these adjustments become too large, a fault code is set.
    When the P0171 code sets, the oxygen sensors are detecting too little oxygen in the exhaust (running "lean") and the control module is adding more fuel than normal to sustain the proper air/fuel mixture.
    • Rich Mixture = Too much fuel, not enough air
    • Lean Mixture = Too much air, not enough fuel

    engine code P0171P0171 fixobd P0171dtc P0171
    obd code P0171obd2 P0171P0171 car codediagnostic code P0171
    car code P0171check engine code P0171fehlercode P0171P0171 fiat
    codigo P0171codigo falla P0171P0171 kody b??dówcodigo de falla P0171

    Powertrain_Control_Module_06.11.png

    What are the common causes of P0171 ?

    This code is typically caused by an engine vacuum leak of lack of sufficient fuel pressure. It is frequently accompanied by a P0171. Probable causes include a clogged fuel filter, faulty fuel pump, an EGR malfunction, or engine vacuum leak/s. Other causes include a fouled or dirty mass air flow sensor, the use of high-performance cold air intake systems that require an oil charged filter element, positive crankcase ventilation system components that are drawing excessive vacuum or leaking, a bad oxygen sensor, an exhaust leak between the combustion chamber and the oxygen sensor, leaking, sticking, or inoperative fuel injector/s.

    What are the symptoms of P0171 ?

    Symptoms include poor acceleration, engine stall under acceleration or at idle, a no start condition, rough engine idle, an engine misfire, or a surge upon acceleration.

    How do you troubleshoot P0171 ?

    The engine system, in conjuction with the engine control module (ECM)/powertrain control module (PCM), activates the P0171 code solenoid valve to control oil pressure to the engine mechanism that is installed in the valve system to switch valve timing between Low and High.If the engine solenoid valve has an open or short circuit, a DTC is stored.



    Searches related to P0171 - System Too Lean Bank 1
    p0171 and p0174
    system too lean bank 2
    p0171 toyota corolla
    system too lean bank 1 and 2
    how do you fix code p0171?
    what is p0171 system too lean
    p0171 chevy
    p0171 ford
     

Share This Page