AutoCodes – Nissan – P0172 Nissan

P0172 Nissan Code - Fuel Injection System Too Rich 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 Faulty Front Heated Oxygen Sensor, Faulty Spark Plugs, Faulty Mass Air Flow (MAF) sensor. 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
P0172 Nissan indicates Fuel Injection System Too Rich Bank 1.
Common causes
Common causes include Faulty Front Heated Oxygen Sensor, Faulty Spark Plugs, Faulty Mass Air Flow (MAF) sensor.
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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 68,099
How popular is this code, among other codes? Medium
Table of contents Created and updated by William Orellana on May 02, 2020
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Code P0172 Nissan 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 P0172 Nissan - Fuel Injection System Too Rich Bank 1 - AutoCodes.com
P0172 Nissan Code - Fuel Injection System Too Rich Bank 1

What are the Possible Causes of the DTC P0172 Nissan?

  • Faulty Front Heated Oxygen Sensor
  • Faulty Spark Plugs
  • Faulty Mass Air Flow (MAF) sensor
  • Exhaust Gas Leaks
  • Ignition Misfiring
  • Incorrect Fuel Pressure
  • Faulty Fuel Injectors

How to Fix the DTC P0172 Nissan?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0172 Nissan 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.

Need more information about the P0172 Nissan code?

Need more information on how to fix the P0172 Nissan code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Nissan Models

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 P0172 Nissan Code

1. What are the common symptoms of OBDII code P0172 in a Nissan?

- Common symptoms include decreased fuel efficiency, rough idling, black smoke from the exhaust, and a strong smell of fuel.

2. What does the OBDII code P0172 "Fuel Injection System Too Rich Bank 1" mean in a Nissan?

- This code indicates that the fuel system in Bank 1 (cylinder bank 1) is delivering a fuel mixture that is too rich (too much fuel compared to air).

3. What are some possible causes of OBDII code P0172 in a Nissan?

- Common causes include a faulty oxygen sensor, issues with the fuel pressure regulator, a clogged or dirty fuel injector, a vacuum leak, or a malfunctioning mass airflow sensor.

4. How can I diagnose the OBDII code P0172 in my Nissan?

- Diagnosing this code typically involves checking the oxygen sensor readings, inspecting the fuel pressure regulator, testing the fuel injectors, checking for vacuum leaks, and verifying the operation of the mass airflow sensor.

5. Can driving with the OBDII code P0172 in a Nissan cause further damage?

- Continuing to drive with a rich fuel mixture can potentially lead to damage to the catalytic converter, oxygen sensors, and other engine components over time.

6. How can I repair OBDII code P0172 in my Nissan?

- Repair options may include replacing a faulty oxygen sensor, cleaning or replacing the fuel injectors, fixing vacuum leaks, replacing the mass airflow sensor, or addressing any other specific component causing the rich fuel mixture.

7. Is it safe to drive my Nissan with the OBDII code P0172 present?

- It is generally not recommended to drive your Nissan with this code present, as it can impact engine performance and potentially lead to further damage if not addressed promptly.

8. Can a dirty air filter trigger the OBDII code P0172 in a Nissan?

- A dirty air filter can restrict airflow, which may affect the air-fuel ratio and potentially contribute to a rich fuel mixture, triggering the P0172 code.

9. How long does it typically take to repair OBDII code P0172 in a Nissan?

- The repair time can vary depending on the specific cause of the rich fuel mixture. Simple fixes like replacing an oxygen sensor may take less time compared to diagnosing and addressing multiple issues.

10. Will resetting the OBDII code P0172 in my Nissan make it go away permanently?

- Resetting the code may temporarily clear the warning light, but if the underlying issue causing the rich fuel mixture is not resolved, the code is likely to reappear. It is important to diagnose and fix the root cause of the problem.

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