AutoCodes – Nissan – P0171 2009 Nissan Altima_sedan

P0171 2009 Nissan Altima_sedan Code - Fuel Injection System Too Lean Bank 1

Quick Answer

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0171 2009 Nissan Altima_sedan indicates Fuel Injection System Too Lean Bank 1.
Common causes: Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 9,985

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 20, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0171 2009 Nissan Altima_sedan Description

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).

OBDII Code P0171 2009 Nissan Altima_sedan - Fuel Injection System Too Lean Bank 1 - AutoCodes.com — P0171 2009 Nissan Altima_sedan Code - Fuel Injection System Too Lean Bank 1

What does this mean?

What are the Possible Causes of the DTC P0171 2009 Nissan Altima_sedan?

Intake air leaks
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Air Flow (MAF) sensor
Incorrect Positive Crankcase Ventilation (PCV) hose connection

How to Fix the DTC P0171 2009 Nissan Altima_sedan?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

If the P0171 is combined with the P0174 code, it's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replace the air filter and clean the air flow meter. If the problem persists the front oxygen (O2) sensor may need to be replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0171 2009 Nissan Altima_sedan code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0171 2009 Nissan Altima_sedan Code

1. What are the common symptoms of OBDII code P0171 (Fuel Injection System Too Lean Bank 1) in a 2009 Nissan Altima sedan?

- Common symptoms include rough idle, lack of power, hesitation during acceleration, and potentially increased fuel consumption.

2. What are the possible causes of code P0171 in a 2009 Nissan Altima sedan?

- Potential causes may include a vacuum leak, faulty oxygen sensor, clogged fuel filter, dirty mass airflow sensor, or a malfunctioning fuel injector.

3. How can I diagnose the root cause of code P0171 in my 2009 Nissan Altima sedan?

- Using a scan tool to check freeze frame data, inspecting the intake system for leaks, testing the oxygen sensor, and checking fuel pressure are some diagnostic steps to determine the cause.

4. Can a dirty air filter trigger the P0171 code in a 2009 Nissan Altima sedan?

- Yes, a dirty or clogged air filter can disrupt the air-fuel mixture, potentially leading to a lean condition and triggering the P0171 code.

5. Is it safe to continue driving my 2009 Nissan Altima sedan with an active P0171 code?

- It is not recommended to drive the vehicle for an extended period with the P0171 code active, as it can lead to engine damage and reduced performance over time.

6. How can I repair the P0171 code in my 2009 Nissan Altima sedan?

- Repair options may include fixing any vacuum leaks, replacing the oxygen sensor, cleaning or replacing the mass airflow sensor, changing the fuel filter, or servicing the fuel injectors.

7. Will resetting the OBDII code temporarily fix the P0171 issue in my 2009 Nissan Altima sedan?

- Resetting the code may temporarily turn off the check engine light, but it will not address the underlying issue causing the lean condition and the code to reappear.

8. Can a faulty fuel pump cause the P0171 code in a 2009 Nissan Altima sedan?

- Yes, a failing fuel pump that cannot deliver enough fuel to the engine can create a lean condition, triggering the P0171 code.

9. Does a bad PCV valve contribute to the P0171 code in a 2009 Nissan Altima sedan?

- A malfunctioning Positive Crankcase Ventilation (PCV) valve can cause a vacuum leak, leading to a lean fuel mixture and the activation of the P0171 code.

10. How long does it take to repair the P0171 code issue in a 2009 Nissan Altima sedan?

- The repair time can vary depending on the exact cause of the lean condition, but it may take anywhere from a few hours to a full day to diagnose and fix the issue properly.