P0492
AIR System Insufficient Flow Bank 2
Secondary air injection / emissions
Generic OBD-II
High
What it means
P0492 means the secondary air injection system isn't pushing enough air into the bank 2 exhaust during cold start-up. This system briefly injects air to heat the catalytic converter faster and cut cold-start emissions; a fault here fails the emissions monitor but does not stop the engine from starting or running.
High
Can I keep driving? Yes — this is a cold-start emissions fault; the car starts and drives normally, but it will fail an emissions test until repaired.
Common symptoms
What you'll notice
- Check-engine light on
- Failed emissions test
- Possible brief rough running just after a cold start
- Air-pump noise absent or abnormal at start-up
Common causes
Most likely first
- Damaged or failed secondary air (AIR) pumpLikely
- Clogged, disconnected, or damaged air hoses to bank 2Common
- Faulty AIR control or bypass valve on bank 2Common
- Blocked air passages from carbon or moisture/corrosionLess often
- Failed AIR system relay or wiringLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the air pump runs at cold start; check for a blown fuse or bad relay if it's silent.
- Inspect the bank 2 air hoses, check valve, and passages for blockage, disconnection, or corrosion.
- Test the AIR control/bypass valve operation and the pump's actual airflow.
- Repair or replace the failed component (pump, valve, hose, or relay), then clear and re-test on a cold start.
FAQ
Quick answers
Is it safe to drive with P0492?+
Yes. Secondary air injection only runs briefly at cold start to warm the catalyst — a fault here doesn't stop the engine starting or running. It will fail emissions until fixed.
Can I just clear P0492?+
It comes back after the next cold-start monitor unless the pump, valve, or hose fault on bank 2 is actually repaired.
Related codes
Often seen with P0492
Read & clear P0492 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX