My 99 F150 RWD has the P0171 code for its running lean any idea where to start


How do I fix code P0171 Ford f150?

  1. STEP 1: USE FIXD TO ENSURE NO OTHER ENGINE CODES ARE PRESENT. …
  2. STEP 2: INSPECT VACUUM LINES. …
  3. STEP 3: INSPECT MASS AIR FLOW (MAF) SENSOR. …
  4. STEP 4: INSPECT EXHAUST SYSTEM. …
  5. STEP 5: CHECK FUEL PRESSURE. …
  6. STEP 6: REPLACE AIR-FUEL AND/OR O2 SENSORS. …
  7. STEP 7: INSPECT AND REPLACE SPARK PLUGS.
  8. Can a dirty air filter cause a P0171 code?

    Can a dirty air filter cause a P0171 code? If the filter is clogged or excessively dirty, this is enough to impede or restrict the air flow, hence resulting in a lean running condition. Besides a dirty air filter, the P0171 code can also be blamed on a dirty or faulty MAF sensor and a clogged fuel filter.

    Why is my f150 running lean?

    A lean fuel condition may exist if the engine is sucking in too much air and/or the fuel system is not delivering enough fuel. If bad enough, a lean fuel condition may cause lean misfire, a rough idle, hesitation or stumble when accelerating, and/or poor engine performance.

    How is P0171 diagnosed?

    How does a mechanic diagnose the P0171 code?

    1. Assuming that no other trouble codes exist, a mechanic may diagnose the P0171 code by checking the engine for vacuum leaks with a vacuum gauge. …
    2. The fuel pressure sensor and MAF sensor (mass air flow) will also be checked with a fuel pressure gauge.

    What causes lean codes?

    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.

    Can an exhaust leak cause a P0171 code?

    An exhaust leak upstream of the O2 is kind of unlikely to cause a p0171, as it would have to be siphoning ‘clean’ air in via venturi effect. A head gasket leak or cracked head will allow the coolant to be burned. this will produce steam and free Ox that the O2 will pick up on. It will read this as lean.

    Where is the MAF sensor located?

    The mass air flow sensor (MAF) is a key component of the electronic fuel injection system in a car. It is located between the air filter and the engine’s intake manifold.

    How do you fix lean air/fuel mixture?

    Vacuum leak: Vacuum leaks can cause a lean fuel mixture. Inspecting and replacing damaged vacuum lines with good hoses and clamps can solve a lean problem. Clogged fuel filter: clogged fuel filters will limit the amount of fuel required by the engine.

    Can a bad O2 sensor cause a P0171 code?

    When the ECM/PCM is having to add too much fuel based on input from the O2 sensor, the fault code P0171 will be sent to the ECM, which will trigger the check engine light to illuminate. This code could either mean that the oxygen sensor is detecting too much oxygen or too little fuel in the mixture.

    How much does it cost to fix a P0171 code?

    You may get lucky with one of the simple repairs mentioned above. A broken vacuum hose sucking in air can be around $50, or a clogged fuel filter for $100. On the other hand, an oxygen sensor or mass air flow sensor can bring a bill of $400 to $500 dollars.

    How do I fix code P1101?

    What repairs can fix the P1101 code?

    1. Replace or repair any faulty, damaged, or loose wiring, connectors, or components within the MAF sensor harness.
    2. Clean or replace the air filter if it is dirty.
    3. Clean the MAF sensor with specialized cleaner. …
    4. Repair any leaks within the vacuum system.

    What causes lean bank1?

    The OBDII trouble code P0171 – System Too Lean (Bank 1) means that the engine air-fuel mixture is too lean, or there is too much air and too little fuel. Driving a car with the code P0171 can cause more damage to the engine over time, as when the engine runs lean, the combustion temperature is higher.

    How do I fix code P0171 and P0174?

    Preventing Damage from Trouble Codes P0171 and P0174

    This is an expensive repair you want to avoid. A simple job like cleaning the MAF sensor or replacing a clogged fuel filter may solve your problem.

    Can you drive with P0171 code?

    It is okay to drive a vehicle with P0171 for a short period of time, but driving with this code for an extended period of time can overheat the engine and cause internal engine damage.

    Can a bad gas cap cause a P0171 code?

    It doesn’t set a code that is false. A lean code from a vacuum leak, mass air flow failure, pcv valve bad or low fuel pressure is 171.

    Why is my car running too lean?

    Because your engine is running on less fuel than it should, it is running “lean.” Your engine running lean is always a symptom of another problem – it could be a dirty MAF sensor, a damaged oxygen sensor, or damaged fuel injectors.

    What are signs that your fuel pump is going out?

    If you notice these six signs, consider taking your car to your local dealership to have the fuel pump replaced.

    • Whining Noise From the Fuel Tank. …
    • The Engine Sputters or Surges. …
    • Trouble Starting the Car. …
    • Loss of Power Under Load. …
    • Reduced Gas Mileage. …
    • Stalling at High Temperatures.