Diagnostic article Generic OBD-II
P0492: bank 2 secondary-air flow and the paired-code clue
P0492 identifies insufficient bank 2 secondary-air flow, and Ross-Tech highlights a specific Audi bulletin when both bank flow faults are stored.
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Documented application
Ross-Tech independent VAG diagnostic guidance; match complete fault description and controller. Vehicle-specific notes do not establish universal applicability.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P0492 concerns insufficient secondary-air flow on bank 2. Ross-Tech's possible causes include the pump's electrical supply, leaking hoses, control solenoids, pressure sensing, combination valves and carbon-blocked head passages. None is established solely by the bank number in the fault.
The other bank's record is useful
The source highlights certain North American Audi 3.0- and 3.2-litre applications where P0491 and P0492 together warrant checking bulletin applicability. That paired-code condition is worth preserving. As diagnostic interpretation, losing the complete fault record can remove a clue that changes which documented procedure is relevant.
The note is not proof that two flow codes always mean carbon blockage. The reference retains the supply, hose, sensor and valve alternatives, and its vehicle list does not establish fitment on unrelated engines.
Bank-specific evidence still matters
A system-wide observation, such as pump operation, does not independently verify that bank 2 received the required flow. Establish the relevant routing and combination-valve arrangement from the engine's repair information. This article describes Ross-Tech's independent guidance, not a universal pressure test or an instruction to clean cylinder-head passages without confirming obstruction. The repair should explain the bank 2 result and any companion bank 1 fault.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
AIR System Insufficient Flow Bank 2
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT