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DTC codes / BMW codes / P1422

P1422 · BMWSecondary Air System Bank 2

P1422 on BMW vehicles indicates that the secondary air injection system for bank 2 is not functioning as expected, meaning the engine computer has detected a fault in the airflow or electrical circuit for that bank. The computer typically monitors the secondary air pump's electrical current and the resulting oxygen sensor response during a cold start, and it sets this code when the expected air delivery is not confirmed.

SystemPowertrain
Code typeBMW specific
SeverityMedium
Fix difficultyIntermediate
AreaAuxiliary emission controls

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms.
  • A slight rough idle or hesitation during the first minute after a cold start.
  • A brief, audible whine or lack of whine from the secondary air pump on cold starts, depending on the failure mode.
  • Increased tailpipe emissions during the warm-up phase, which may be noticed during an emissions inspection.
  • In rare cases, a stored pending code without the light if the fault is intermittent.

Common causes, most likely first

  1. Failed secondary air pump motor or seized pump bearing on bank 2.
  2. Blown fuse or corroded relay supplying power to the bank 2 secondary air pump.
  3. Damaged or disconnected vacuum line to the bank 2 combi valve, preventing it from opening.
  4. Stuck-closed or carbon-fouled bank 2 combi valve, blocking air flow into the exhaust manifold.
  5. Cracked or disconnected air injection hose between the pump and the combi valve.
  6. Faulty bank 2 oxygen sensor slow response, causing the computer to misinterpret the air injection test.
  7. Wiring harness damage or poor ground connection at the secondary air pump or combi valve.

How to diagnose and fix it

  1. Verify the code with a BMW-specific scan tool and check for any related pending or stored codes in the secondary air system.
  2. Inspect the fuse and relay for the secondary air pump, and test for battery voltage at the pump connector during a cold start.
  3. Listen for the secondary air pump to run for the first 30 to 90 seconds after a cold start, and compare bank 1 and bank 2 operation if accessible.
  4. Check all vacuum lines and air hoses from the pump to the bank 2 combi valve for cracks, disconnection, or blockage.
  5. Command the bank 2 combi valve open with the scan tool and verify that air flows through the valve, or remove and inspect it for carbon buildup.
  6. Test the bank 2 oxygen sensor response and compare it with bank 1 to rule out a sensor that is slow or lazy during the air injection test.
  7. Repair or replace the faulty component, clear the code, and perform a cold-start drive cycle to confirm the repair.

Before you replace the secondary air pump

  • A clogged or stuck-closed combi valve on bank 2 is frequently the real culprit, and replacing the pump without checking the valve will leave the code unresolved.
  • The secondary air pump only runs for a short period after a cold start, so a fault may not appear during a warm-engine inspection and the pump may seem fine when tested hot.
  • Carbon buildup in the bank 2 exhaust port can block the air passage even when the combi valve and pump are working, so a visual check of the port is essential.
  • A lazy bank 2 oxygen sensor can mimic a secondary air fault because the computer relies on the sensor's response to confirm air delivery, so always compare sensor switching times.
  • On some BMW engines, a failing non-return valve in the vacuum supply to the combi valve causes intermittent P1422 without any pump or valve failure.

Can I keep driving with P1422?

You can generally continue driving with P1422 because the fault mainly affects cold-start emissions and does not cause immediate engine damage. Avoid long periods of idling from cold and schedule diagnosis soon, especially if you have an emissions test due.

Tools that help

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Guidance is general and written for BMW vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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