P0174 Nissan Code – Meaning, Symptoms, Causes, Fixes, Cost and Prevention Measures

Has the “Check Engine” light suddenly popped up on your Nissan’s dashboard? Did a scan reveal the P0174 Nissan Code? If you own popular models like the Nissan Altima, Maxima, Pathfinder, or Sentra, you may be all too familiar with this trouble code. But what does this code mean? And more importantly, how can you resolve it? This comprehensive guide is here to help, covering everything from the meaning and symptoms of the P0174 code to its causes, fixes, and prevention measures.

If you’ve previously encountered the P0101 Nissan Code in Sentra, Altima, Rogue, and Maxima, you’ll know how important it is to understand these codes. By the end of this guide, you’ll be well-equipped to handle the P0174 issue, ensuring your Nissan continues to provide a reliable, smooth ride.

Understanding P0174 Nissan Code

The P0174 Nissan Code is a diagnostic trouble code (DTC) that your vehicle’s onboard computer generates when it detects an issue in the Fuel Injection System, specifically with Bank 2 running too lean. But what does ‘running too lean’ mean? In simple terms, it indicates that there’s an excess of air and a lack of fuel in your engine’s fuel-air mixture.

When your engine is running lean, it can lead to a host of problems such as poor engine performance, decreased fuel efficiency, and in severe cases, engine damage due to overheating. To prevent such issues, it’s important to understand and promptly address the P0174 code.

Symptoms of P0174 Nissan Code

Recognizing the symptoms associated with the P0174 code can help you catch and address the issue early. Often, you may notice the ‘Check Engine’ light illuminating on your dashboard. Besides this, your vehicle may exhibit signs like:

  • Decreased engine performance: Your vehicle might struggle to accelerate or may stall frequently.
  • Increased fuel consumption: A lean fuel condition can decrease your vehicle’s fuel efficiency, leading to increased fuel consumption.
  • Rough idling: You might notice your vehicle idling roughly or unevenly, particularly when you’re at a stop.

The presence of any of these symptoms along with the illuminated ‘Check Engine’ light should prompt you to have your vehicle inspected.

Causes of P0174 Nissan Code

The P0174 code can be triggered due to various reasons. Let’s delve into the common ones:

  • Faulty Mass Airflow Sensor: The mass airflow sensor measures the volume of air entering the engine. A faulty sensor might not provide accurate readings, causing the engine to run lean.
  • Oxygen Sensor Malfunction: The oxygen sensor in your vehicle monitors the level of oxygen in the exhaust gases. A malfunctioning sensor can provide incorrect readings, leading to a lean condition.
  • Vacuum Leaks: Vacuum leaks in the engine can introduce additional air into the engine, disrupting the air-fuel mixture balance.
  • Issues with Fuel Injectors or Fuel Pump: If the fuel injectors are clogged or if the fuel pump is not working efficiently, it might result in less fuel being delivered to the engine.

Understanding these causes can help in effectively diagnosing and fixing the issue.

Common Fixes for P0174 Nissan Code

Fixing the P0174 code usually involves addressing the root cause of the problem:

  • Mass Airflow Sensor: You might need to clean or replace the mass airflow sensor to ensure it provides accurate readings. Here’s a helpful guide on cleaning your mass airflow sensor.
  • Oxygen Sensor: If a faulty oxygen sensor is the issue, replacement might be the solution. Here’s an informative tutorial on how to replace an oxygen sensor.
  • Vacuum Leaks: Check for any vacuum leaks in the engine and repair them. This video provides a great visual guide on how to find and fix vacuum leaks.
  • Fuel Injectors and Fuel Pump: Service the fuel injectors and fuel pump to ensure they are functioning properly.

Always remember, if you’re not confident doing these tasks yourself, take your vehicle to a professional mechanic.

Video Solution

Estimated Cost for P0174 Nissan Code Repair

The cost of fixing a P0174 Nissan Code can range significantly depending on the issue. For simple fixes such as sensor replacements, you might be looking at around $100-$200, including labor. However, more complex repairs like servicing the fuel injectors or fuel pump can push the cost to $500 or more.

Prevention Measures

The key to preventing the occurrence of the P0174 code lies in regular maintenance of your vehicle. Ensure you replace sensors as per the manufacturer’s recommendation, maintain the fuel system regularly, and promptly address any performance issues or ‘Check Engine’ light warnings. Regular vehicle servicing can help spot and address issues before they escalate, saving you from expensive repairs in the long run.


In conclusion, the P0174 Nissan Code signifies an issue with your vehicle’s fuel system that should not be ignored. By understanding its symptoms, causes, and fixes, you can ensure a smooth and efficient ride. Remember, preventative maintenance is your best friend when it comes to avoiding these issues.

If you found this article helpful, consider sharing it with your fellow Nissan owners. Stay tuned for more informative guides on vehicle diagnostics and repairs.