Engine-CodesInfiniti – P0402 Infiniti

P0402 Infiniti Code - Exhaust Gas Recirculation Flow Excessive Detected

Quick Answer

The P0402 code in an Infiniti vehicle indicates that the exhaust gas recirculation (EGR) flow is excessive. Common causes include Malfunctioning EGR valve, Clogged EGR passage, Faulty EGR position sensor. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means
P0402 Infiniti indicates Exhaust Gas Recirculation Flow Excessive Detected.
Common causes
Common causes include Malfunctioning EGR valve, Clogged EGR passage, Faulty EGR position sensor.
Severity
Moderate - service should be scheduled soon.
Can I drive?
The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Table of contents Created and updated by William Orellana on Sep 12, 2024
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Code P0402 Infiniti Description

The P0402 code in an Infiniti vehicle indicates that the exhaust gas recirculation (EGR) flow is excessive. The EGR system is designed to reduce nitrogen oxide emissions by recirculating a portion of the exhaust gases back into the engine intake. When the EGR flow is excessive, it means that there is an abnormal amount of exhaust gases being reintroduced into the combustion chambers. This can lead to a variety of issues, including decreased engine performance, increased emissions, and potential damage to the engine components.

OBDII Code P0402 Infiniti - Exhaust Gas Recirculation Flow Excessive Detected
P0402 Infiniti Code - Exhaust Gas Recirculation Flow Excessive Detected

Common Causes of P0402 Infiniti

  1. Malfunctioning EGR valve
  2. Clogged EGR passage
  3. Faulty EGR position sensor
  4. EGR solenoid issues
  5. Vacuum leaks in the EGR system

Symptoms of P0402 Infiniti

  1. Rough idling or stalling
  2. Decreased fuel efficiency
  3. Engine hesitation or surging
  4. Check Engine Light illuminated
  5. Increased emissions

How to Fix P0402 Infiniti

  1. Diagnose the specific cause of the excessive EGR flow by using a scan tool to monitor EGR system data and perform a visual inspection of EGR components.
  2. Clean or replace the EGR valve to ensure proper operation.
  3. Inspect and clean the EGR passage to remove any obstructions that may be causing the excessive flow.
  4. Test the EGR position sensor and replace if necessary to ensure accurate feedback to the engine control module.
  5. Check the EGR solenoid for proper function and replace if faulty to regulate the EGR flow effectively.

Cost to Fix P0402 Infiniti

The cost of repairing a P0402 code in an Infiniti vehicle can vary depending on the specific cause of the issue and the labor rates at the repair shop. Generally, the parts required for the repair, such as a new EGR valve or sensor, can range from $100 to $300. Labor costs can add an additional $150 to $300, with total repair costs typically falling between $250 and $600. It's important to note that these estimates are rough averages and that actual costs may vary based on location, vehicle make and model, and the extent of the repairs needed.

When is the Code Detected?

High Exhaust Gas Recirculation (EGR) flow control is detected

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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 P0402 Infiniti Code

1. What are the common symptoms of OBDII code P0402 in an Infiniti?

- Common symptoms include poor engine performance, rough idle, decreased fuel efficiency, and the illumination of the check engine light.

2. What are the possible causes of OBDII code P0402 in an Infiniti?

- Potential causes include a faulty EGR valve, clogged EGR passages, carbon buildup, wiring issues, or a malfunctioning EGR temperature sensor.

3. How can I diagnose the source of OBDII code P0402 in my Infiniti?

- Diagnosing the code involves checking the EGR valve for proper operation, inspecting the EGR passages for blockages, testing the EGR temperature sensor, and verifying the integrity of related wiring.

4. Can a dirty air filter cause OBDII code P0402 in an Infiniti?

- While a dirty air filter may not directly cause P0402, it can contribute to carbon buildup in the EGR system, potentially leading to issues triggering the code.

5. How can I prevent OBDII code P0402 from coming back after repairs in my Infiniti?

- Regular maintenance, such as cleaning the EGR system, using high-quality fuel, and addressing engine performance issues promptly, can help prevent the recurrence of P0402.

6. Is it safe to continue driving with OBDII code P0402 present in my Infiniti?

- It is generally not recommended to drive with code P0402 present, as it can lead to further engine damage and decreased fuel efficiency if left unresolved.

7. What are some DIY repair tips for fixing OBDII code P0402 in an Infiniti?

- DIY repair tips include cleaning the EGR valve and passages, checking and replacing the EGR temperature sensor if needed, and ensuring all related wiring is in good condition.

8. Can a malfunctioning EGR valve cause other issues besides triggering OBDII code P0402 in an Infiniti?

- Yes, a faulty EGR valve can also lead to engine knocking, rough idling, decreased power, and increased emissions if not addressed promptly.

9. Are there any software updates or recalls related to OBDII code P0402 for Infiniti vehicles?

- It is recommended to check with your local Infiniti dealership or service center to inquire about any software updates or recalls related to code P0402 for your specific vehicle model.

10. How long does it typically take to repair OBDII code P0402 in an Infiniti?

- The repair time for code P0402 can vary depending on the exact cause and complexity of the issue. It can range from a quick fix like cleaning the EGR system to more involved repairs that may take several hours to complete.

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