AutoCodes – Chevrolet – P0420 2014 Chevrolet Silverado

P0420 2014 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 2014 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.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,976

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0420 2014 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 2014 Chevrolet Silverado - Catalyst System Low Efficiency Bank 1 - AutoCodes.com — P0420 2014 Chevrolet Silverado Code - Catalyst System Low Efficiency Bank 1

What does this mean?

What are the Possible Causes of the DTC P0420 2014 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 2014 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 2014 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 2014 Chevrolet Silverado code?

Need more information on how to fix the P0420 2014 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0420 2014 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 2014 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P0420 on a 2014 Chevrolet Silverado?

- Common symptoms include a check engine light, reduced fuel efficiency, and a possible sulfur smell coming from the exhaust.

2. What causes the OBDII code P0420 Catalyst System Low Efficiency Bank 1 on a 2014 Chevrolet Silverado?

- The code is often triggered by a failing catalytic converter, oxygen sensor issues, exhaust leaks, or engine misfires.

3. Can a bad oxygen sensor cause the P0420 code on a 2014 Chevrolet Silverado?

- Yes, a faulty oxygen sensor can provide inaccurate readings to the engine control module, leading to the triggering of code P0420.

4. How can I diagnose the root cause of the P0420 code on my 2014 Chevrolet Silverado?

- Diagnosing the issue may involve inspecting the catalytic converter, checking oxygen sensor functionality, examining for exhaust leaks, and verifying proper engine performance.

5. Is it safe to continue driving my 2014 Chevrolet Silverado with the P0420 code illuminated?

- It is generally safe to drive the vehicle with the code, but it is recommended to address the underlying issue promptly to prevent potential damage to the catalytic converter.

6. Will resetting the OBDII code P0420 on a 2014 Chevrolet Silverado make it go away permanently?

- Resetting the code without fixing the underlying issue will likely result in the code reappearing once the vehicle's ECM detects the problem again.

7. How much does it typically cost to repair the P0420 code on a 2014 Chevrolet Silverado?

- The cost of repair can vary depending on the specific cause, but it may involve replacing the catalytic converter, oxygen sensors, or addressing exhaust leaks. Costs can range from a few hundred to over a thousand dollars.

8. Can using lower-quality fuel contribute to the triggering of the P0420 code on a 2014 Chevrolet Silverado?

- Poor-quality fuel or a fuel system issue can potentially impact the efficiency of the catalytic converter and lead to the triggering of code P0420.

9. Are there any DIY repair tips for addressing the P0420 code on a 2014 Chevrolet Silverado?

- DIY tips may include checking for visible exhaust leaks, ensuring the oxygen sensors are functioning correctly, and monitoring engine performance for any signs of misfires.

10. How can I prevent the OBDII code P0420 from reoccurring on my 2014 Chevrolet Silverado after repair?

- To prevent code P0420 from reoccurring, it's essential to address any underlying issues promptly, perform regular maintenance on the vehicle, use quality fuel, and drive the vehicle responsibly.