P0492: AIR System Insufficient Flow Bank 2
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes.
Symptoms
- Check engine light
- Cold-start smell
- Emissions failure
Likely causes, most common first
- Bank 2 branch blocked
- Bank 2 check valve failed
- Split hose on that side
- Carbon in the ports
Read P0492 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0492 is insufficient secondary air on bank 2 - the mirror of P0491, and the same one-bank-versus-both-banks reasoning applies.
Check valves fail asymmetrically for a real reason: exhaust pulses and heat differ slightly between banks, so one valve cooks before the other. When one is found leaking, the other has lived the same life; on engines where the valves cost little and sit accessibly, changing both is cheap insurance against doing the same job twice a season apart.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Frequently asked questions
Can I drive with P0492?
Yes.
How much does it cost to fix P0492?
Typical US repair costs range from $60 for the simplest fix (hose repair) to $600 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0492. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.