P0492 Code: Secondary Air Injection System Insufficient Flow (Bank 2)

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on January 31st, 2024

Reading Time: 3 minutes
Summary
  • The P0492 code stands for “Secondary Air Injection System Insufficient Flow (Bank 2).”
  • This is logged when the powertrain control module (PCM) detects that the secondary air injection system isn’t supplying enough air to the bank 2 side of the engine.
  • A clogged or disconnected vacuum hose, faulty secondary air pump control valve, electrical issues, and obstructed air injection passages are common reasons why on-board diagnostics (OBD) will log this code.
  • Aside from an illuminated check engine light, an increase in tailpipe emissions is the only other noticeable symptom for this code.

Some cars use a secondary air injection system to reduce tailpipe emissions. Depending on the vehicle, the system may supply air to the exhaust manifolds, the catalytic converter, or both at different times. The additional air helps reduce harmful exhaust gases through oxidation. The catalytic converter also warms up more quickly when air is added to the exhaust manifolds.

If the secondary air injection system develops a fault on the bank 2 side of the engine, the PCM will log a P0492 code.

What Does the P0492 Code Mean?

The Diagnostic Trouble Code (DTC) P0492 indicates “Secondary Air Injection System Insufficient Flow Bank 2.”

Most secondary air injection systems consist of an air pump, air management solenoids, necessary plumbing, and one or more check valves. To manage the flow of air through its passageways, the system opens or closes the valves.

Some cars use a secondary air injection system to reduce tailpipe emissions.

In engines with two cylinder banks, the secondary air injection system typically supplies additional air to both banks.

The PCM regularly checks how much air flows through the secondary air injection system. If the computer notices that the system isn’t sending enough air to bank 2, it will set the powertrain code P0492.

Read our advanced discussion about secondary air injection systems to better understand codes like P0492.

Note: The definition of code P0492 may differ according to the vehicle manufacturer. Check the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P0492 Code?

What are the Common Symptoms of the P0492 Code?

How to Diagnose the P0492 Code

The P0492 is a generic powertrain code. It applies to OBD II-compliant vehicles.

If you’re not confident about conducting diagnostic tests on your vehicle, it’s a good idea to bring it to a certified mechanic. Otherwise, you may go ahead and diagnose the issue yourself.

To help you get started, here is a video that may give you an idea of what the process might involve:

How to Fix the P0492 Code

Attempting to fix a P0492 code may become a frustrating task if you don’t have the right tools and know-how to test the secondary air injection system. In most cases, it’s best to leave the job to a professional.

For DIYers with advanced technical knowledge and hands-on experience, who prefer to test and repair their vehicle on their own, it will be helpful to rely on the appropriate repair manual or refer to an online repair database.

Order a Replacement Vacuum Hose in the Comfort of Your Home

If your vacuum hose causes the P0429 code to set, it’s a good idea to replace it immediately. Exhaust system issues can cost considerable sums to fix, and they can cause your vehicle to fail its next emissions test. CarParts.com makes finding a compatible replacement vacuum hose fast and effortless.

You don’t have to go to a physical store to get a new vacuum hose anymore, as you can order one in the comfort of your home. Use your mobile phone to access CarParts.com, and enter your vehicle’s details in our vehicle selector to bring up compatible parts. We only source our vacuum hoses from reputable manufacturers, so you know you’re getting a quality part. Our products are also ready to ship from one of our strategically located warehouses, so you can get your order in just a few business days.

Check out our wide selection of vacuum hoses at CarParts.com and shop now.

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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Published by
CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician
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