P2442: Secondary Air Injection System Switching Valve Stuck Open Bank 2
What to do
Expect poor economy and a rough idle. If the fuel trims on the two banks disagree sharply, with only one bank reading lean, that pattern fits this fault well — air is being pumped into the exhaust on that side and the sensor cannot tell it from a lean mixture. Mention it, because it saves a vacuum leak hunt that would find nothing.
What this code means
The bank 2 switching valve is not closing. The mechanism and the misdiagnosis it causes are set out in full at P2440: air entering the exhaust outside the cold-start window makes that bank's oxygen sensors report a lean mixture that does not exist, and the module over-fuels in response.
The bank split adds a genuinely useful signature. Because the false lean reading is confined to the bank whose valve is stuck, the fuel trims diverge between banks — one bank railed positive while the other sits normal. That asymmetry is hard to explain any other way, and it is visible on a scan tool without removing anything.
Likely causes
Start here
- Carbon deposits holding the valve open · moderate
- Faulty secondary air switching valve · moderate
- Failed secondary air check valve · moderate
Less common
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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