P0161: O2 Sensor Heater Circuit — Bank 2 Sensor 2
What to do
No driveability impact, but the catalyst monitor will not complete until it is fixed.
What this code means
A heater circuit fault on the downstream bank 2 sensor, overlapping with P0056. Rear sensors depend heavily on their heaters because exhaust gas has cooled considerably by the time it reaches them.
Likely causes
Start here
Less common
- Road damage to underfloor wiring · 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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