AutoCodes – Chevrolet – P0420 2015 Chevrolet Silverado

P0420 2015 Chevrolet Silverado Code - Catalyst System Low Efficiency Bank 1

Quick Answer

A 3-way catalyst controls emissions of hydrocarbons, Carbon Monoxide (CO), and Nitrogen Oxide (NOx). 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 2015 Chevrolet Silverado indicates Catalyst System Low Efficiency 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 1,558

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 Jun 20, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0420 2015 Chevrolet Silverado Description

A 3-way catalyst controls emissions of hydrocarbons, Carbon Monoxide (CO), and Nitrogen Oxide (NOx). The catalyst within the converter promotes a chemical reaction, which oxidizes the hydrocarbons and the CO that are present in the exhaust gas. This process converts the hydrocarbons and the CO into water vapor and carbon dioxide (CO2), and reduces the NOx, converting the NOx into nitrogen. The catalyst also stores oxygen. The Engine Control Module (ECM) monitors this process by using Heated Oxygen Sensors (HO2S) that are in the exhaust stream before and after the 3- way catalyst. The HO2S produces an output signal that the ECM uses to calculate the oxygen storage capacity of the catalyst. This indicates the ability of the catalyst to convert the exhaust emissions efficiently. The ECM monitors the efficiency of the catalyst by monitoring the HO2S during an off-idle, Decel Fuel Cut-Off (DFCO) event. When the catalyst is functioning properly, the post-catalyst HO2S response to the fuel conditions during the DFCO event is slow compared to the response of the pre-catalyst HO2S. When the post-HO2S response is near that of the pre-HO2S, the oxygen storage capability and efficiency of the catalyst may be degraded below an acceptable threshold. The Diagnostic Trouble Code (DTC) will be set when the ECM determines that the efficiency of the catalyst has degraded below a calibrated threshold.

OBDII Code P0420 2015 Chevrolet Silverado - Catalyst System Low Efficiency Bank 1 - AutoCodes.com — P0420 2015 Chevrolet Silverado Code - Catalyst System Low Efficiency Bank 1

What does this mean?

What are the Possible Causes of the DTC P0420 2015 Chevrolet Silverado?

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 2015 Chevrolet Silverado?

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 (it 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 2015 Chevrolet Silverado 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 2015 Chevrolet Silverado code?

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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 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P0420 in a 2015 Chevrolet Silverado?

- Common symptoms include the check engine light turning on, reduced fuel efficiency, and potential loss of engine power.

2. What does the OBDII code P0420 "Catalyst System Low Efficiency Bank 1" mean for a 2015 Chevrolet Silverado?

- This code indicates that the catalytic converter on Bank 1 is not performing efficiently, possibly due to issues with the converter itself or the engine's emissions.

3. What are the possible causes of OBDII code P0420 in a 2015 Chevrolet Silverado?

- Causes can include a faulty catalytic converter, oxygen sensor issues, exhaust leaks, engine misfires, or problems with the fuel system.

4. Can driving with the OBDII code P0420 in a 2015 Chevrolet Silverado cause further damage?

- Continued driving with this code may lead to further damage to the catalytic converter, reduced engine performance, and potential harm to the environment.

5. How can I diagnose the OBDII code P0420 in my 2015 Chevrolet Silverado?

- A proper diagnosis involves checking the catalytic converter, oxygen sensors, exhaust system for leaks, and inspecting the engine for misfires or fuel system issues.

6. Is it safe to continue driving my 2015 Chevrolet Silverado with the OBDII code P0420?

- It is generally not recommended to drive for an extended period with this code as it can affect the vehicle's performance and lead to more significant issues.

7. What are some repair options for fixing OBDII code P0420 on a 2015 Chevrolet Silverado?

- Repair options may include replacing the catalytic converter, repairing or replacing faulty oxygen sensors, fixing exhaust leaks, and addressing engine misfires.

8. Can a DIY enthusiast resolve OBDII code P0420 in a 2015 Chevrolet Silverado?

- While some aspects of diagnosing and repairing this code may be tackled by a DIY enthusiast, resolving the underlying issues often requires professional expertise and equipment.

9. How much does it cost to fix OBDII code P0420 on a 2015 Chevrolet Silverado?

- The cost of repairs can vary depending on the specific issue causing the code, but it may range from a few hundred to over a thousand dollars, especially if catalytic converter replacement is needed.

10. Will resetting the OBDII code P0420 in a 2015 Chevrolet Silverado make it go away permanently?

- Simply resetting the code without addressing the underlying issue will not fix the problem permanently; the issue must be diagnosed and resolved to prevent the code from reappearing.