Quick answer: The heater circuit for the downstream oxygen sensor on Bank 2 is not operating correctly.
Drivers also search this fault as bank 2 sensor 2 heater circuit, downstream O2 heater fault bank 2, rear oxygen sensor heater code bank 2.
P0161 is the Bank 2 counterpart to P0141. It points to the heater circuit for Bank 2 Sensor 2, the downstream oxygen sensor after the catalyst on Bank 2. The downstream sensor is used mostly for catalyst-monitoring and emissions logic rather than direct fuel control, but its heater still matters because the sensor must wake up reliably for the ECU to trust the Bank 2 rear signal after startup.
P0161 is often driveable short-term because major drivability issues are uncommon, but Bank 2 emissions readiness and related catalyst diagnostics can stay incomplete until it is fixed.
Cause phrases often tied to this code: rear oxygen sensor heater failure bank 2, wiring damage, connector corrosion, fuse issue, heater ground problem.
Brand hubs help broaden internal linking now and can evolve into make-specific diagnostic notes later.
Useful when the driver knows the wording but not the exact DTC yet.
Yes. Both are downstream oxygen-sensor heater-circuit codes, but on different banks.
No. It points to the heater circuit for the Bank 2 rear O2 sensor, not directly to converter failure.
Yes. Rear O2 heater wiring on Bank 2 lives in a hot, exposed area and often fails there first.