P2430: Secondary Air Injection System Air Flow Pressure Sensor Circuit Bank 1
What to do
The car drives normally; cold-start emissions monitoring is affected, which matters at an emissions test. Worth knowing that this sensor is the one that checks whether air actually reaches the exhaust, as opposed to whether the pump is being told to run — so if secondary air faults have been chased electrically without resolution, this is the measurement that would have settled it.
What this code means
A fault in the circuit of the sensor that measures what the secondary air injection system is actually delivering on bank 1.
This sensor exists because the control circuit codes at P2257–P2260 cannot answer the question that matters. Those report whether the module can drive the pump and the valves. They cannot tell whether any air reached the exhaust — and on this system that gap is wide, because the characteristic failures are physical rather than electrical:
- The check valve seized, which blocks the path while the pump runs perfectly.
- The plumbing coked up, since it delivers air into an exhaust manifold and carbon accumulates at the junction.
- The pump spinning but not pumping, its impeller corroded by the exhaust moisture the check valve was supposed to keep out.
In every one of those the electrical side is faultless and no air arrives. The flow sensor is what closes that gap, which makes it more diagnostically valuable than its position in the numbering suggests.
A fault in the sensor itself therefore costs the ability to verify delivery, and the practical consequence is an incomplete monitor — the module cannot confirm the system works, so it reports that rather than a failure.
Likely causes
Start here
- Corroded or loose connector · easy
- Faulty secondary air flow sensor · moderate
- Damaged wiring harness · moderate
Less common
- Failed secondary air check valve · moderate
- Blown fuse or failed supply · easy
Symptoms
Components involved
Information, not instruction
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Community experience
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- The car — make, model, year and engine. The same fault behaves differently on each.
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