P2416: O2 Sensor Signals Swapped Bank 1 Sensor 2/Bank 1 Sensor 3
What to do
This is a wiring mistake rather than a failed part, and correcting it costs nothing. If the exhaust, heat shields or oxygen sensors have been worked on recently, say so — that is when it happens. Do not let a catalytic converter be replaced while this code is stored, because the readings the converter would be judged on are coming from the wrong sensors.
What this code means
The module has concluded that the second and third sensors on bank 1 are connected the wrong way round. This is the installation-error family described in full at P2278, applied to two sensors on the same bank rather than across banks.
Same-bank swapping is if anything easier to do than cross-bank, because the two sensors sit in the same exhaust run, are frequently the same part number, and their connectors are within reach of each other. Nothing physical prevents it and nothing complains at the time.
The consequence is that the module judges the first catalyst using the sensor after the second one, and vice versa — so catalyst efficiency readings become meaningless in a way that looks plausible rather than broken. A converter diagnosed on the strength of those readings is being condemned on evidence that was never valid.
The fix is free: swap the connectors back.
Likely causes
Start here
Less common
- Incorrect oxygen sensor fitted · moderate
- Damaged wiring harness · moderate
Rare
- Faulty oxygen sensor · moderate
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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