AutoCodes – Chevrolet – P0422 Chevrolet

P0422 Chevrolet Code - Catalyst 2 Low Efficiency

Quick Answer

The main function of the Diesel Oxidation Catalyst (DOC) is to control emissions of non-methane hydrocarbons and Carbon Monoxide (CO). Common causes include Faulty Oxidation Catalytic Converter, Faulty Diesel Particulate Filterâ€‰(DPF). Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0422 Chevrolet indicates Catalyst 2 Low Efficiency.
Common causes: Common causes include Faulty Oxidation Catalytic Converter, Faulty Diesel Particulate Filterâ€‰(DPF).
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,039

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Sep 23, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0422 Chevrolet Description

The main function of the Diesel Oxidation Catalyst (DOC) is to control emissions of non-methane hydrocarbons and Carbon Monoxide (CO). Its secondary function is to assist with the Diesel Particulate Filter (DPF) regeneration, by obtaining and sustaining the temperature necessary for regeneration. In order to generate the high exhaust temperatures needed for regeneration, the aftertreatment system increases exhaust temperatures by injecting diesel fuel into the exhaust system via post-injection. The injected fuel is converted into heat by the DOC to incinerate soot accumulated in the DPF. The Engine Control Module (ECM) monitors the exhaust gas temperature sensor 3, 4, and 5 to determine if the operating temperature of the catalyst is achieved during a DPF regeneration.

OBDII Code P0422 Chevrolet - Catalyst 2 Low Efficiency - AutoCodes.com — P0422 Chevrolet Code - Catalyst 2 Low Efficiency

What does this mean?

What are the Possible Causes of the DTC P0422 Chevrolet?

Faulty Oxidation Catalytic Converter
Faulty Diesel Particulate Filterâ€‰(DPF)

How to Fix the DTC P0422 Chevrolet?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0422 Chevrolet 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 P0422 Chevrolet code?

Need more information on how to fix the P0422 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0422 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

P0422 2014 Chevrolet Silverado — Catalyst 2 Low Efficiency
P0422 2015 Chevrolet Silverado — Catalyst 2 Low Efficiency
P0422 2016 Chevrolet Silverado — Catalyst 2 Low Efficiency
P0422 2017 Chevrolet Silverado — Catalyst 2 Low Efficiency
P0422 2018 Chevrolet Silverado — Catalyst 2 Low Efficiency

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 P0422 Chevrolet Code

1. What does the OBDII code P0422 mean on a Chevrolet?

P0422 indicates that the second catalytic converter is operating below the efficiency threshold set by the vehicle's engine control module (ECM).

2. What are the common symptoms of the P0422 code on a Chevrolet?

Symptoms may include the check engine light turning on, reduced fuel efficiency, poor engine performance, or a failed emissions test.

3. What causes the P0422 code in a Chevrolet?

Common causes include a failing catalytic converter, a faulty oxygen sensor, exhaust leaks, or engine issues like misfires or rich/lean fuel mixtures.

4. Can a bad oxygen sensor trigger the P0422 code?

Yes, a faulty upstream or downstream oxygen sensor can provide incorrect readings to the ECM, leading to the P0422 code.

5. How serious is the P0422 code on a Chevrolet?

While it may not cause immediate drivability issues, ignoring the code can lead to increased emissions, poor performance, and potential damage to other components.

6. How do you diagnose the P0422 code on a Chevrolet?

Diagnosis involves checking for exhaust leaks, inspecting the catalytic converter, testing oxygen sensor performance, and using a scan tool to monitor live data.

7. Can you drive with the P0422 code on a Chevrolet?

Driving is usually possible, but itâ€™s recommended to address the issue promptly to avoid further damage or failing an emissions test.

8. How is the P0422 code fixed on a Chevrolet?

Repairs may include replacing the catalytic converter, oxygen sensors, fixing exhaust leaks, or addressing engine issues like misfires.

9. How much does it cost to fix the P0422 code on a Chevrolet?

Costs vary but may range from $200 for an oxygen sensor replacement to $1,000 or more for a catalytic converter replacement, depending on parts and labor.

10. Can a dirty air filter cause the P0422 code on a Chevrolet?

While unlikely, a dirty air filter can contribute to improper air-fuel mixture, which may indirectly cause catalytic efficiency issues over time.