AutoCodes – Nissan – P0420 2010 Nissan Pathfinder

P0420 2010 Nissan Pathfinder Code - Catalyst System Efficiency Below Threshold Bank 1

Quick Answer

The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor). Common causes include Faulty Three-way Catalyst Converter Bank 1, Exhaust Tube, Intake Air Leaks. 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: P0420 2010 Nissan Pathfinder indicates Catalyst System Efficiency Below Threshold Bank 1.
Common causes: Common causes include Faulty Three-way Catalyst Converter Bank 1, Exhaust Tube, Intake Air Leaks.
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.

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Code Popularity 9,261

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 20, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0420 2010 Nissan Pathfinder Description

The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).
A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.

OBDII Code P0420 2010 Nissan Pathfinder - Catalyst System Efficiency Below Threshold Bank 1 - AutoCodes.com — P0420 2010 Nissan Pathfinder Code - Catalyst System Efficiency Below Threshold Bank 1

What does this mean?

What are the Possible Causes of the DTC P0420 2010 Nissan Pathfinder?

Faulty Three-way Catalyst Converter Bank 1
Exhaust Tube
Intake Air Leaks
Faulty Oxygen (O2) Sensor
Faulty Fuel injector(s)
Leaking Fuel Injector (s)
Faulty Spark plugs
Improper Ignition Timing
Faulty Engine Control Module (ECM)
Dirty Air Filter

How to Fix the DTC P0420 2010 Nissan Pathfinder?

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

As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0420 2010 Nissan Pathfinder 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 P0420 2010 Nissan Pathfinder Code

1. What are the common symptoms of OBDII code P0420 on a 2010 Nissan Pathfinder?

- Common symptoms include a check engine light, decreased fuel efficiency, and reduced engine performance.

2. What does the OBDII code P0420 "Catalyst System Efficiency Below Threshold Bank 1" mean on a 2010 Nissan Pathfinder?

- This code indicates that the catalytic converter is not performing efficiently in terms of emissions reduction.

3. What are the possible causes of OBDII code P0420 on a 2010 Nissan Pathfinder?

- Causes can include a faulty catalytic converter, oxygen sensor issues, exhaust leaks, or engine misfires.

4. How can I diagnose the cause of OBDII code P0420 on my 2010 Nissan Pathfinder?

- Diagnosing may involve checking the oxygen sensor readings, inspecting the catalytic converter, and looking for exhaust leaks.

5. Can a bad oxygen sensor trigger OBDII code P0420 on a 2010 Nissan Pathfinder?

- Yes, a malfunctioning oxygen sensor can lead to incorrect readings and trigger code P0420.

6. What are some repair tips for addressing OBDII code P0420 on a 2010 Nissan Pathfinder?

- Repair tips may include replacing the catalytic converter, fixing any exhaust leaks, or replacing faulty oxygen sensors.

7. Is it safe to continue driving my 2010 Nissan Pathfinder with OBDII code P0420?

- While the vehicle may still be operational, it's advisable to address the issue promptly to prevent further damage and maintain emissions compliance.

8. Can resetting the check engine light temporarily resolve OBDII code P0420 on a 2010 Nissan Pathfinder?

- Resetting the light may temporarily clear the code, but it won't fix the underlying issue causing the code to appear.

9. How much does it typically cost to repair OBDII code P0420 on a 2010 Nissan Pathfinder?

- Repair costs can vary depending on the specific cause, but they may range from a few hundred to over a thousand dollars, especially if the catalytic converter needs replacement.

10. Are there any preventative measures to avoid OBDII code P0420 on a 2010 Nissan Pathfinder?

- Regular maintenance, such as timely replacement of oxygen sensors and addressing engine issues promptly, can help prevent the occurrence of code P0420.