AutoCodes – Honda – P0420 2019 Honda CR-V

P0420 2019 Honda CR-V Code - Catalyst System Efficiency Below Threshold

Quick Answer

The Three-Way Catalytic Converter (TWC) converts Hydrocarbons (HC), Carbon Monoxide (CO), and Oxides of Nitrogen (NOx) in the exhaust gas to water vapor, Carbon Dioxide (CO 2), and Dinitrogen (N 2). Common causes include Faulty Three-Way Catalytic Converter (TWC), Faulty Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)), Secondary Heated Oxygen Sensor 2 harness is open or shorted. 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 2019 Honda CR-V indicates Catalyst System Efficiency Below Threshold.
Common causes: Common causes include Faulty Three-Way Catalytic Converter (TWC), Faulty Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)), Secondary Heated Oxygen Sensor 2 harness is open or shorted.
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 476

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 18, 2023

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0420 2019 Honda CR-V Description

The Three-Way Catalytic Converter (TWC) converts Hydrocarbons (HC), Carbon Monoxide (CO), and Oxides of Nitrogen (NOx) in the exhaust gas to water vapor, Carbon Dioxide (CO 2), and Dinitrogen (N 2). The Powertrain Control Module (PCM) fluctuates the air/fuel ratio temporarily to detect the performance of the TWC and measures the degree of fluctuation in the secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2)) output. If the accumulated value for a set time is too great, deterioration of the performance of the catalyst is detected, and the PCM detects a malfunction and stores a Diagnostic Trouble Code (DTC).

OBDII Code P0420 2019 Honda CR-V - Catalyst System Efficiency Below Threshold - AutoCodes.com — P0420 2019 Honda CR-V Code - Catalyst System Efficiency Below Threshold

What does this mean?

What are the Possible Causes of the DTC P0420 2019 Honda CR-V?

Faulty Three-Way Catalytic Converter (TWC)
Faulty Secondary Heated Oxygen Sensor (Secondary HO2S (Sensor 2))
Secondary Heated Oxygen Sensor 2 harness is open or shorted
Secondary Heated Oxygen Sensor 2 circuit poor electrical connection

How to Fix the DTC P0420 2019 Honda CR-V?

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 Powertrain Control Module (PCM) has detected that the Three-way Catalyst Converter is not working properly (it is not as efficient as the factory expects). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases, the Three-way Catalyst Converter needs to be replaced to resolve the problem. If the P0420 code is combined with other codes, try addressing the other codes first.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0420 2019 Honda CR-V 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 P0420 2019 Honda CR-V code?

Need more information on how to fix the P0420 2019 Honda CR-V code? Get Access to Factory Service Manuals

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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 2019 Honda CR-V Code

1. What are the common symptoms of OBDII code P0420 on a 2019 Honda CR-V?

The common symptoms of code P0420 in a 2019 Honda CR-V include decreased fuel efficiency, reduced engine performance, and the illumination of the check engine light.

2. What does the OBDII code P0420 Catalyst System Efficiency Below Threshold mean for a 2019 Honda CR-V?

Code P0420 indicates that the catalytic converter in the exhaust system of the 2019 Honda CR-V is not operating at the efficiency levels required for proper emission control.

3. What are the possible causes of OBDII code P0420 on a 2019 Honda CR-V?

Common causes of code P0420 on a 2019 Honda CR-V include a faulty catalytic converter, oxygen sensor issues, exhaust leaks, engine misfires, or a malfunctioning fuel system.

4. Can driving with OBDII code P0420 on a 2019 Honda CR-V cause further damage?

Continuing to drive with code P0420 on a 2019 Honda CR-V can potentially cause damage to other components of the vehicle, such as the oxygen sensors or the engine, and may lead to increased emissions.

5. How can I diagnose the cause of OBDII code P0420 on my 2019 Honda CR-V?

Diagnosing code P0420 on a 2019 Honda CR-V typically involves checking the catalytic converter, inspecting the oxygen sensors, looking for exhaust leaks, and ensuring proper engine performance.

6. Are there any DIY repair tips for fixing OBDII code P0420 on a 2019 Honda CR-V?

DIY repair tips for addressing code P0420 on a 2019 Honda CR-V include checking for loose or damaged components, replacing faulty oxygen sensors, and ensuring proper maintenance of the vehicle's engine.

7. Should I reset the check engine light after fixing OBDII code P0420 on my 2019 Honda CR-V?

After fixing code P0420 on a 2019 Honda CR-V, it is recommended to reset the check engine light using an OBDII scanner to ensure the issue has been resolved and to monitor for any new problems.

8. Can a catalytic converter cleaner fix OBDII code P0420 on a 2019 Honda CR-V?

Using a catalytic converter cleaner may temporarily improve the efficiency of a catalytic converter, but it is not a long-term solution for resolving code P0420 on a 2019 Honda CR-V.

9. How much does it typically cost to repair OBDII code P0420 on a 2019 Honda CR-V?

The cost of repairing code P0420 on a 2019 Honda CR-V can vary depending on the specific cause of the issue, but it may range from a few hundred to over a thousand dollars, especially if the catalytic converter needs replacement.

10. Can I pass an emissions test with OBDII code P0420 present on my 2019 Honda CR-V?

Having code P0420 present on a 2019 Honda CR-V will likely cause it to fail an emissions test, as the catalytic converter is not operating efficiently enough to meet the required emissions standards.